JPTL

59 front is close enough to specs. to make a noticeable improvement over less offset wheels. The 3.6 style that RH makes are 3 piece, so you'll pay. (RH Wheels US). They make a much less expensive one piece (AG) that looks good on our cars as well.
The RAL (what I have on my car) is a very nice wheel in a two piece.
Going from a 17" Boxster S wheel with a 55 offset on SXX 225's to the more correct RAL's on 18" 235 PS 2's w/59 offset, there was a noticeable improvement in handling. Partially due to the excellent handling of the PS2's, but also less 'tramlining' than with the 55 offset.

Shark Attack

With enough money, anything will fit.

Erling G-P

I was hoping perhaps the Keskins and original RH 3.6s would look sufficiently similar, so that I could limit myself to replacing the fronts, but must admit I doubt it.

Cheers,
Erling

Vilhuer

Keskin cost 1/3 or 1/4 of what RH list price is. If there is 4-5mm extra material in front wheels which could be removed they would be much better fit.

Erling G-P

Don't think I would even dare contemplate this, for fear of the wheels breaking - which would most likely happen when they're in a high-load situation, meaning you're in even more severe trouble.

Cheers,
Erling

Vilhuer

Its not something I would do lightly either but I know it has been done without problems. Not to these exact Keskin wheels though. It would be easier to contact manufacturer and ask if they would consider making special set of wheels with ET closer to 70mm. They could be interested especially if there would be several people who are interested. Even if price were 2x or 3x normal rate its still less than full set of RH's.