Cayman Islands 1sh Black/Green With No Identifiable Watermark

This is either a Scott # 27 or a 29. The only difference I can see between the two would be the watermark, with the 27 having wmk. 3 and the 29 having wmk. 2. Pretty easy to distinguish the two watermarks; so no issues on identification on my end, other than I cannot make out a watermark whatsoever. Nada, nothing.

Perfs check out at 14 (for both stamps, of course.)

Paper looks and feels right (I took out some other Caymans/Jamaica of the same ilk just to check.)

Any suggestions/help here?

Scans attached if they are of any help, and thank you.

How about 27 is on chalky paper .

Andy, these issues on coloured paper are notoriously difficult to see watermarks on. It may be there, but very faint. As far as I am aware, no issues are known without a watermark and geometrically it's impossible for there to be a space between that stamps without a watermark.

If the Crown CA watermark is displaced a little, then only a portion of it may be there, making your job all the more difficult. This may be what has happened with your stamp?

Statistically speaking, Scott 27 which has the Multiple Crown CA (MCA) watermark is much more likely. More stamps were produced with the MCA watermark than the Crown CA version.
Try looking at it against black paper under spotlamps - the kind they sell at office supply stores. Sometimes that helps the watermark show.
Generally speaking the Crown CA watermark tends to be more centered whereas the MCA watermark is not. So if you even see one letter (C or A) somewhere other than in the bottom middle of the stamp it will certainly be the MCA watermark (Scott 27). Notice the arrangement on the scans to see what I mean.

Floortrader - Both the 27 and 29 are on chalky paper; so I was confirming that the paper was legit (not that I'd expect a forgery of this sort, but one never knows.) Also why I am leery of attempting the remove the hinge remnants to get a better view. I've read that exposing chalky paper to any sort of liquid is not good. (Anyone care to verify or elaborate?)

Thank you both Tim and KGVI; between the Caymans, Jamaica and Ceylon have seen enough of these to know what I'm looking for (or should be) but this is the first time I'd found something in which I couldn't find anything!

Much appreciated all.