Stamps (Philately)/Sheet plate block....
Is it more valuable if it has a serial number still attached, or doesn't it matter? What about if it is a block of 4 or 6 or more? I also have a complete roll (coil?) of stamps an cannot find a value. The stamps are; Jefferson, Red, 2 cent, 1954, Scott #1055. Also in black ink across the front is pre-cancelled; Cedar Rapids, Iowa.
The roll is complete, unused, still tightly wound. Any help would be appreciated! Thanks!
Stamps in "Multiples" can come in many forms. If we have two from a sheet they will be "Pairs" either vertical or horizontal. In older stamps these would have lines that ran up the middle vertically and horizontally. If your block has one of these lines it's known as a "Guide Line" block and if the "selvage" (the area outside the actual stamp) is attached with slanted \/ (one or both) it might be considered an "Arrow" guide line block. In the very middle this block will have both the horizontal and vertical lines, known as a "Center Line Block". These are the most valuable generally, because there can be only 1 per sheet.
Plate blocks (Size varies from 4 to as many as 10) to qualify will have to be a full number of attached stamps to equal a block, PLUS the selvage AND the block number still attached. (These aren't serial numbers... they represent the "plate" that the sheet was printed from. Usually there are 2 - 4 variations, but you'll find many with the number and the plate numbers for all US stamps are known, even back to Scott #1). Serial numbers, like you find on printed bills are sequential and unique, and stamps don't use that. Generally speaking the book value of a "Plate Block" will be more than just a block of 4, but large blocks of 20 or 50 without selvage will likely be more valuable than a plate block. Obviously the older the block and the higher denomination (face value) of the stamp will tend to make for most valuable plate blocks.
Now, on to coils... as you mentioned some stamps come on rolls. These are known as coils and stamps my have been coiled in top to bottom or side to side fashion, known as Horizontal or Vertical coils. (The Horizontal or Vertical refers to the perforation side, NOT the flat side). So stamps that are perforated top and bottom are "Horizontal Coils" and Vertical is the side-to-side. In my memory (I could be wrong on this) at least with US stamps, I can't think of an example where they horizontally coiled a stamp and didn't also vertically coil it, but after around 1940, all the coils I can think of are vertically perfed only.
Coils, even in singles are worth more than there sheet counterparts in every case. Why you may ask? All coils (at least up to 1940) were made from existing stamp engravings. They were put onto rolls because as postage became more useful, the ease of applying large lots came from using coil stamps. They also became the preferred method of "vending machine" stamps. But, there were always far fewer coils made than sheet stamps. "Availability" or lack thereof is one of the key drivers of stamp value.
Two coil stamps joined together are a "Coil Pair". Like the lines on sheets that I mentioned before, and because these were initially made from the same sheets as sheet stamps (they just spliced them together) you get the "guide line" that I mentioned before occurring every so often on a roll of stamps. This is known as a "Joint Line Pair" and are more valuable than just a "Pair", because those with lines are more scarce. Interestingly in some cases, cancelled versions of the coil stamps have a higher value then their Mint (or at least Unused with Hinge mark) counterparts. This is especially true of some of the 1908 - 1920 Washington/Franklin issues.
Now a roll... is a different animal. Rolls came in many sizes: 100, 250, 500... up to 10,000 in modern day coil rolls. So the size of your roll will drive what it's value is. The larger the roll the better, as fewer and fewer would exist as the size increased. Unfortunately you've described them to me as what is known as "Bureau Pre-Cancelled". That will affect the value of your roll, because despite having perfect gum on the back, it is still considered a "Used" stamp with the precancel on it, and the 1055 isn't one of the stamps that benefits from higher value being used than unused. Still, its a roll and in tact, so that's not trivial. Also, it's from an era when "Joint line pairs" were still in use.
One other aspect that is interesting and possible here though is, you COULD have a very valuable roll on your hands. This stamp also came in with two perforation hole sizes (Large and small). If this were a small hole roll, it would be VERY valuable. They are both Perf 10 on a perf gauge, but the way to determine them easily is, if the width of the paper between holes is wider than the width of the hole, they are small hole. If the width of the hole is wider than the width of the paper between them, then they are large hole.
In either case, a roll of this age and even if only 100 is still notable. It will be difficult to price it. And the "used" nature of a coil roll will likely impact it as well. For example, a Joint Line Pair of small hole coil has a book value of 60 cents, while a MINT pair has a catalog value of $50! So the gap between mint and used here is significant. I had a glace at eBay but did not find a 1055 roll selling there in recent history. A small hole pre-cancel pair sells for about $1, with Joint Line Pairs selling on eBay for about $2. You can probably "guess" at a value of your roll then from current market pricing. To be sure of the hole size, I would suggest finding a local dealer if that is convenient for you, and have them validate the size.
Hope that helps,