From what i understand the caliper mounted wings were fitted to the early 280mm VR6 Girling brakes and wont fit any others due to the mounting point. The Other type that vent from the front bumper openings were fitted to certain TDI's to aid intercooler airflow.
wrong, the vents that come from the front bumper lip does aid brake cooling as it was fitted to pre88 models GTI 16V witch still had the 239mm brakes from the gti 8V. The 1988models(starting mid 1987) the gti 16V got 256mm brakes with girling54 calipers.
As for the little wings on the calipers: probably correct. However I think they will fit any girling 54 caliper it you change the brakeline bracket to vr6.
updates:
the 'wings' and suspension assembled, got a leather OEM documentbook aswell.
undertray