Bigpapa...I am pushing 69 years old. I still every now and then get in a ring to work with a fighter..but now I suit up with head gear, pad, etc. and maybe will go 3-4 rounds with the other fighter holding back on his punches. I was boxing in my 30's---but one thing I began to learn was that I was losing speed, and reaction time. Yes, there are people who are exceptions to this...for awhile anyway. Nature will began to slow you up, you will find that injuries do not heal as quickly, you will find that you tire quicker--in short--the more you fight at your age, the sooner you are going to meet that fighter who is going to hurt you. Most gyms, because of liability insurance coverage will not allow you to fight beyond training and demonstration.
The final decision is yours. But I have a friend now who is blind in one eye and has trouble with balance because he could not admit there comes a time when you need to get out of the ring. He was 34 when it happened.