Quote.

“Curious if modern shooting coats etc. are allowed with the modern springers?

Also I assume given many vintage BSA had aperture sights that they were allowed in the “original“ vintages matches?”.

I don’t know about original vintage matches but,
Dressing in “Gimpy” coats, cardboard trousers, clown size boots would be frowned upon in our “Vintage rifle comp. aperture sights, as long as period would be accepted.
DaveM.