De 32 icebox conversion; factory insulation improvements anyone? General Forum Forums

Any one know the quality Of the factory insulation at the ice box? I'll be installing an Isotherm unit with the holding plate and galley sink through hull condenser. Shame on me for redoing my counter tops, all the trim, and painting all the fiberglass panels in the galley around the ice box. So I'm thinking I'm just gonna have to add an 1" or 2" of corecell ( I think rvalue is approx 5 per 1") to the inside epoxy it to the inside then put a layer of glass over it. Rather then rip it all out..or I was contemplating  drilling a hole on each side and pouring some expanding foam ( the kind you mix up that's made for ref.) But I'm Leary it'll leak out and end up every where I don't want it. Any chance I could be lucky and the factory insulation is good enough?