Here's the 3 options I see:
Ranked in order of however I feel like ranking them.

Option 1: Fill the entire slot with epoxy/filler and then put the screws into it just like the newer boats have.

Option 2: Permanently epoxy the rope in place, leaving the webbing loops exposed. This was suggested by Mischa Heemskerk to solve this problem, as well as to stop the leaks that will develop in the track.
Right TJPECO?

Option 3: Use the biggest piece of line you can get into the track for the boltrope.

Option 4: Upgrade! I've got an '06 I'll let go...

I like options 1 and 4 the most.