You'll have no problem if you present it clean and don't argue. The lack of charcoal canister may be an issue. I recently had to get my escort blue slipped (been off the road for 3 years). I jammed a canister into it. Plumbed the vacum line to a blank on the air box and carby and the return to tank was a hose that disappeared into my rail. It looked legit so the gentlemen didn't ask questions. I failed on non original seats.
The car car Mk2 2.0L had a non standard carby, extractors, 2.25 inch exhaust, bigger brakes, wheel spacers and 16inch RS Focus wheels (which both the spacers and wheels have since gone, I hated them), rear mounted battery. What else is illegal without a cert that it had... can't remember but he failed me on non original seats because the seats in it didn't use the original runners and didn't slide back and front. Throw in 35 year old crappy seats and it passed.
I was nice to the guy and when it came in for a recheck he didn't even crack the bonnet.