I'd keep the first
9 for the registry number, but would get rid of (at most) one of the numbers, to bring it closer to, not only the late-24th/early/mid-25th-century, but also would keep it in the same
millenium, considering that Starfleet hasn't gone anywhere near that six-digit number of registry.
So it would be one of these numbers:
NX/NCC-99525
NX/NCC-93525
NX/NCC-93925
NX/NCC-93955
NX/NCC-93952
With that said, I may not be a fan of Enterprise, but
"Azati prime" [ENT] gave me a new outlook on future Trek in a way or two, and keeping with how Gene tried visioning the later centuries of Star Trek as he would vision humanity's optimistic future, I'd say it's a good idea if this Khitomer-class was more of a Federation ship, if you can imagine sometime in the 25th or 26th centuries the Klingons joining the Federation.
But if so, and if ships would require a six-digit registry number, I'd add a
1 to my suggestions for a registry number.
And the ship model itself is well done. I'm impressed.