Woodie, it's a ca finish. If it's looking gummed up.....either the ca wasnt completely dry when you're sanding it ...or maybe its ca residue from the sanding. It looks whitish and is very hard to get out.
The way I have found to be the easiest for me is..... finish the call out completely, polishing and all.....then turn your lines in and when finished,I use the edge of a piece of paper towel soaked with ca and carefully insert the edge into the line. I use the thin ca for this. Just be careful to get it only in the groove and not on the finished call. I usually put 2 coats in the groove with this method. Thats how this call is finished. I dont try to polish the groove afterwards because the white in the polish is hard to get out too!
Hope this helped,
David