Cryptic crossword No 836

Thanks for the puzzle Owlbazaar, some lovely stuff in here, particularly 13a (neat), 14a (smooth), 16a (clean), 19a (satisfying), 28a (clean), 1d (neat), 6d (very clean), 7d (likewise), 15d (neat assembly), 22d (neat) and 24d (neat)...

I really like the indicator word in 1a. Never seen it before.