These are one of the recommended sets for the slk with wider rearsI'm sure Wheelbase have a compatibility section so you can cross-check, just make sure they know the front & rear wheels are different widths. Phone them if still unsure.
The style you favour was fashionable many years ago & the many Allen key-like bolt heads around the perimeter quickly rusted or got tarnished & were a pain to keep clean.
It would be good to see a set fitted or similarI considered putting 'lots of spokes' wheels on my 170, but I figured it'd be a pain to clean off brake dust and keep them in good order.
In the end I caved and bought a more minimal (but smart) 5 spoke split design from Wheelbase.
I think these would look great on a 171 (bar those hideous center caps), especially on a silver. If you like them and they suit your tastes; go for it.