The US and UK models of the Silver Streak did differ, this can be demonstrated by viewing UK/US marketing literature. Some came with SR type alloy seatpost clamps, while others had Suntour, the US adverts promoted the SR clamp which the HL had. If you want to be picky about wheels, make sure they are are fully anodised black rims, and not shine sides.
The chainwheel, in most instances were Sugino 44T, that's not to say they didn't come with HL styles. Another noticable difference can be the grips, of which there were three types, Foam over Vinyl, F1 type and Cobra.
I purchased my SS from my cousin, who had it from new, which is in the museum, though I did put the era correct grips and brakes back on (I prefer front and rear), apart from that, it's how it came out of the shop with the drilled chainwheel, which is probably an optional extra.
Sparky