A lot of things are collectible on that piece.
The meter is, the markings or stampings, to a postal historian or appreciator, and the stamps/
Probably on
ebay dot com is best as that is in the USA and I look at it.


The Grand Central Station stamps with the well-p[laced and lovely readable cancel is a collectible to me, a cancel collector and appreciator. If sold separately from the Super Heroes stamps then please cut around the clear tape I think I can see close to them, but leave as much white paper (or cardboard ?) as possible.
I think the Super Heroes would sell better as they are in a large block or group, on paper, nicely cancelled and when sold, all the Super Heroes mentioned by name so the benefits and features of each are emotionally remembered by the reader, hopefully bidder.