I thought this to jack, 4BIM, but the Colour combo doesn't match and more importantly the Base in the advert is not Als base. Look at the where the side chute goes, there are 2 slits. This is the second generation base as you say, but Als is a 6th gen F62 base, the first of this kind. The giveaway is there are no slits for the chute, als base has two lugs cast into the base where the chute attaches via a pin and spring..
So this is where my confusion lies...Early engine correct colour on a later base. There are 3 more bases between the one in the ad and Als F62.
Anyways It looks the part and who knows what was done back then...Maybe the early base intersected with als on a much closer timeline and they still had the early engines left over.
