EDITS:

6.0" x 14 or 15in rims will fit with a +38 offset (checked at the mag shop) but only leave about 2-3mm between rim and strut.... nowhere near enough.

6.0" x 14 or 15in with a +35 offset fit with a reasonable amount of clearance i.e. a bit more than 5-8mm (couldn't actually measure, but they looked ok)

May depend on the rim as well, because the second set (14 X 6, +35) had more than an extra 3mm clearance. These rims had 185/70/14's on them and there was clearance all round, but it was only a couple of mm at the tyre sidewall.

Does anyone know how much sidewall bulge you get out of a 195/50/15 on a 6" rim

As for the +2 rule (W.A.) all of the guy's in the shops said dont worry about it, you will never get picked up for having 15"s unless the cop/inspector is a datsun guru and knows that 1200's came out with 12" not 13".