I found some more information ala Google:
At that URL search for these two articles:
Bottom-bracket confusion – 2004.07
Axles and Cranks – 2000.03
Basically the spindle ends on JIS spindles (like Shimano) are a tiny bit fatter than ISO (like Stronglight). If you put an ISO crank on a JIS bb it won't slide all the way on. This means that you probably can't use the same spindle length as before because the cranks stick out a bit further...so predicting spindle length can be a bit tricky.
There might be a risk of ruining the cranks; because the crank can't completely seat onto the spindle there can be room for a bit of play if they're not tightened enough. And if they ARE tightened down with a lot of torque you risk permanently deforming the crank's spindle interface. Once you do that it sounds as if you can not install that crank on an ISO spindle again (although the author of the question in second article counters this).
The first article points to Sheldon Brown's comments on the matter at
"ISO cranks (Campagnolo, Stronglight, others) won't go as far onto J.I.S. spindles as they ideally should.
J.I.S. cranks (most Japanese models) may bottom out if installed on ISO spindles.
In practice, you can very often get away with mixing these sizes, as long as you select an axle length that gives the desired chainline."
At one point I posted a question on this forum about which Phil Wood spindle tapers would work for old Stronglight cranks ("standard" taper is the answer from Brent at Phil by the way). In his reply to my question, unworthy1 wrote
"Phil Wood, in their wisdom, chose to make a 3rd option (the "Standard") that splits the difference between the ISO and JIS SPINDLE SIZES and creates one spindle end that is "universal" as far as it applies to regular JIS and older European cranks (which is all that used to be on the planet, square-taper wise). But because their "universal standard" was by definition going to be slightly different from the spindle length you are replacing, you have to check with Phil, either look up on the Phil chart or call them, to insure you buy the right length for your application."
I guess I'll just have to try it and see. Once the bike is built up again (pending frame restoration) I'll post my findings...might be several months. Thanks everyone.