The bike will not hold you back. A 48 year old pro showed up to a local race a few weeks ago. His only bike was an 89 Honda CR 500. It looked as if it had been washed once in 1980, then put away. Rusty, leaking fork seals, worn out chain, etc.
Obviously no one cared if he entered the 250 pro class. He was riding for fun on a clapped out bike. He lapped up to third place in a 9 lap moto.
Your old machine should be fine. He would have lapped everyone if he would have had a bike as good as yours.