it hard to say without knowing what options were available at the time aye
the later version sl and sr i know a few differences... ie nz built SR has cream interior, 3k-b twin carb engine, 3-2-1 exhaust manifold, SR badges, plastic woodrain veneer dash, tacho, center console, U series 4.55:1 ratio diff, different hub caps, twin brake master cylinder. (thats what mine came with) some had aluminium twin brake master cyl with remote reservior. but as said it can vary.
late SL had black interior, 3k, black dash. a bit more plain than the SR, kinda similar to the earlier delux model.
earlier models had all sorts of interior colours like blue, orange, brown, green, black. roof lining is always cream from the ones ive looked at.
the tail lights are different between the early and late ke25's. the late ones are same tail light and grill between sl and sr that ive seen.
the early ke25's have heaps of grill variations.
i can email pics if you wish.
im compiling a comparison of variations so hopefully have that on my website one day