It's a pity that you don't know someone with one(st170) that you could try your wheel on.
Failing that, I don't see that they are going to fit, most 15" have 335mm or thereabouts clearance(inside), ST170 = 300 discs plus caliper, so it's not going to.
What about the cossie route ?, four pots and 283mm discs.
tabetha