So the real trivia question - was this aircraft in basic BCal colours as a result of the Metropolitan/BCal Commuter tie-up, or because it was previously operated as G-BKIE by Genair which went bust in early 1984 (?) and so was painted like that anyway? Looking at the state of the paint scheme where the previous markings have been crudely whited out, I'd say the latter!!
The re-registration from G-METO to G-METP followed Metropolitan's failure - CAA G-INFO says that happened on 6-9-1985. It was fairly standard back in the day to do that as a means of keeping away from liens being imposed for previous operators' debts - just like the Court Line One-Elevens into Dan-Air and the Laker DC10-10s into BCal Charter. Computer flight tracking has changed all of that!