I'm beginning to think these old TOM OF FINLAND booklets I have might indeed be originals, and the ones with the glossy covers are 1980's reprints.... just a guess. But doing as much googling as I can manage, I see these paper ones from the mid/late 1960's, and the glossier ones seem to have come out in the 1980's.

up for auction Tom Of Finland - BEACH BOYS 1 ( ends SUNDAY - item #180050453503)
up for auction TOM OF FINLAND - Jack In The Jungle 2 ( ends SUNDAY - item #180050476916)
up for auction TOM OF FINLAND - Jack In The Jungle 3 ( ends Tuesday - item #180051299309)
up for auction TOM OF FINLAND Kake No. 13: Sightseeing (ends Tuesday - item #180051308336)