Is This A 550A First Day??

Just going through a whack load of Centennials I got at an auction.(Funny thing about the 50th anniversary.) And not really a centennial being printed in 1971. But what I think I found was a 550a block canceled Dec. 30th 1971. There is a score line between going vertical.
Wondering really what the value would be on this. Unitrade has $750 for pair MNH and nothing more.
Thanks for any info.

These are normal coil stamps from un-separated strips and as such are only a small premium over the normal coil stamps. These unseparated strips are not uncommon. The imperf stamps you refer to would not have the horizonatal perforations and so would be impref all round.

The first day of issue used would increase the value somewhat but my guess is that they are philatelic and as I do not collect these I cannot comment on the value but I am sure someone will.

AQ

Thanks Anthraquinone, I figured that would be the deal. Was wondering though why would they not have it in Unitrade as a variety. Such as 604 and 605 imperf horizontally.

Have a look at this link from an earlier thread

https://goscf.com/t/18847&whichpage=1

It explains what you want to know

AQ

Yes Anthraquinone that is exactly what I wanted to know. Thank you.