I have a Miyata hybrid c. mid 1990's that probably needs a new crank as it seems pretty warped. All 3 chainrings wobble by the same amount which tells me the crank is warped. The axle is fine. Back in the old days, a hammer would do the trick but this is an aluminum crank.
Exage 300 LX
(Shimano FC M300)
Shimano Biopace SG chainrings 28/38/48.
I've looked at the compatability chart, and the cranks with the same axle dimension requirements don't seem to be available in the main stream retail places I've looked.
What's current and compatible?