Hey Cogar,, are you sure we didn`t go to different schools together ?? I use the caulk too for small areas !! Was shocked to hear that anyone else used it too !! And if its thinned down and brushed on it will stabilize all those tiny cracks in a frame !! You are right,, if its close and painted with a good gold paint,, you really can`t see it !! Only problem with this frame is that its an entire side that needs to be replaced so it would pretty much have to be molded !!
As for cleaning, fix the tear first, I have had pretty good results if its a small tear,, by using surgical tape on the back, then I get my acrylic paint and blend matching colors over the exposed canvas fibers !! Clean after all that is dry with 1 oz baby shampoo + 1 tsp bleach or peroxide in about 1 1/2 C. water !! Just use a soft cloth and wet it in the solution and squeeze most of the water out and rub gently to remove grime !! Then do the same with clear water !! Do not try to clean the back, work only on the front !! Dry at least a couple of days !! Once oil paint and acrylic paint are dry and cured they are pretty stable, the canvas is the part you need to be careful with !!