Great. A few weeks ago another that I sent to the USA was returned to me, no reason given. So I'm now a bit nervous sending to the USA.
I've emailed you a PDF of the Irish book.
The light striations in the obverse fields indicate it might well have been wiped or cleaned in the past.
As for polishing - is the mirror finish only in the fields but not the raised design (difficult to tell from those pictures)? If yes, then not polished, but if shiny all over then it most likely has been.
The double plume 1887 crown represents about 5% of the population. It is recorded and mentioned in a paper submitted to BNS blog but not yet published. Several of them were in The Thorburn Collection sold by Sovereign Rarities 23rd. Sep. 2025. notably lot 81