Everythings grey, yes but no but yes but no.
I'd not see the difference in that import than an aliexpress parts import.
Again aslong as they are legal parts to own e.g mags, furniture, it's fine. (Supressors have to be dummy)
I've not had customs issues or courier delivery issues, only courier issues when exporting - they are a fussy bunch.
Sending larger packs for a while then suddenly oops DPD actually scanned the box - had to drive half the country to collect.
imo its a gamble you'd win 80% of the time but you do you and do not use this as advice because its bad advice based on luck.
You could contact someone who deals in this stuff, but if you're not a customer I don't know how much time he'd give you.
He's closed till next month or longer (heading to ukraine), his websites formatting has broken a bit.
But ive even seen him sell real 9x39 VSS mags which are damn rare.
https://www.cold-war-collectables.co.uk/parts-department/soviet-weapons-parts/
Deals in real steel deacs etc. - super jelous of his real AN-94, Bizon .etc
https://www.facebook.com/ColdWarCollectables2/
It's also a shame Rusmilitary do not have Zenitco for offer as they are Russian, importing and selling Russian firearms & Accessories.
(though I was unable to purchase something from them out of stock due to the sanctions)
http://www.rusmilitary.com/
They even have a full sanction breakdown with loophole statement at the end just food for thought reading not that it matters imo (I'll avoid politics)
http://www.rusmilitary.com/html/uk_sanctions.htm