My thoughts exactly- and if he's even been in a wreck before and STILL doesn't wear the gear? That tells me something was broken LONG before the accident..At 40 years old, there's probably nothing you can say that will change his mind. I'm sure he knows your fellings on the gear thing. Just let him know you're not in the mood to be looking for a new friend when he's gone!
The only thing I could think of is getting him to check out the airbrushed brain buckets or helmets- maybe the design will help wake him up to wearing one? Other than that, fugghedaboutit.
BF