Belly lam sounds like a good solution. Just started a blackthorn bow, think I 'll harvest the lams from that. Would you take the opportunity to glue in a little reflex?
Nope, I wouldn't add reflex, it's prob hard enough to brace anyway, and will that just be adding new problems?!
Mind, if the draw length is now less than you have pulled it to before you could add maybe a whisker.
Also as it's sinew backed it could be good. You need some of the sinew guys to chip in.
Del