For inspiration on how to reinforce to mounts, I had to look no further than my other pantera. That car is a pre-production car chassis #1267. This car came from the factory with substantionally reinforced a-arm, shock and sway bar mounts.
From what I've been able to figure out, only the very first 286 cars had these add-ons (I may be wrong though).
Spot the differences ?? - I Count 9 reinforcementplates