There are two primary varieties of this stamp. One stamp has the “F” denomination which follows the letter designations used by previous rate change stamps. The other has the 29¢ denomination.
The “F” stamp comes in 4 varieties, of which two will take a small amount of time to identify them. The sheet stamp, with perforations on all 4 sides is Scott #2517. The coil stamp with perforations on the right and left sides only is Scott #2518. Scott #2519 and #2520 are the booklet stamps that take a little work. Scott #2519 uses a brighter yellow background and the grenn leaf is printed in a darker green color. Scott #2520 uses a pale yellow background color and a bright green color for the leaf. If you see two stamps side by side, it’s very easy to spot the differences.
The 29¢ denominated stamp comes in five varieties. Again, only two of them take a little effort. Scott #2524 is the perf 11 sheet stamp. Scott #2524A is the perf 13 by 12.75 sheet stamp. Scott #2524A is more scarce and a plate block of #2524A catalogs $50. When buying mint postage, keep your eyes open and you might pick up #2524A instead. There are two coil issues. Scott #2525 is rouletted (it has tiny slits between the stamps). Scott #2526 is perf 10. And lastly, Scott #2527 is the booklet stamp.
In summary:
Scott # | Design | Format | Perf | Notes |
2517 | F | Sheet | 13 | |
2518 | F | Coil | 10 | |
2519 | F | Booklet | 11 | Bright yellow background and dark green leaves |
2520 | F | Booklet | 11 | Pale yellow background and bright green leaves |
2524 | 29¢ | Sheet | 11 | |
2524A | 29¢ | Sheet | 13 by 12.75 | More scarce than #2524, especially the plate block |
2525 | 29¢ | Coil | Rouletted | Small slits separate the stamps, not perforations |
2526 | 29¢ | Coil | 10 | |
2527 | 29¢ | Booklet | 11 |