Marcantilan,
I searched for Op SHUTTER on-line and found this RAF HQ STC Operational Research Branch report from 1983 - originally classified SECRET UK EYES A - with analysis of the Argentine Air Effort.
I guess you have already seen it as part of DEFE 58/274 but I thought I would post it for others to see. It is an interesting read.
Examination of Argentine Air Effort - Arcre