Personally, I'd switch over from DR2 to 5/16" or 3/8" Robline racing sheet and splice 3/16" spectra into where it runs through the blocks. I did this on my 20 and it is wonderful!
As far as bulking up the cover goes, I would buy some 3/8" Samson Trophy Braid (cheap, yet very grippy), and pull the core out.
If I remember correctly, we used to just whip the ends down semi-tapered, and the ran a sewing machine on the new cover part.
I think it will probably be more trouble than it is worth. Definitely consider switching to Racing Sheet.