Spring Heater Box Cleaning - Damage Found

I have an assy as well from a 68 if you need it. Check out my ad "68 notch back" under parts cars for sale.
If u found something to slide inside that outlet that would be a nice easy fix.
Thanks. I'll keep that in mind. I'm going to try the repair in a couple of weekends (have a family birthday party this weekend so no time to work) and if no go, I'll be in touch on it!