Probably 8 x 32 x 1/2. Missing strap, if its just a piece of nylon webbing, Ace hardware carrys webbing, if its velcro, try a fabric shop. Sounds more like you need a whole new case! Maybe I can help.
"Skin that one, and I'll get ya another"
2 06 Martin Slayers, 63 & 55#s Nitrous C X QuikTune 3000s and HHA OL 5519s on both.
04 Martin Cougar Elite Nitrous C X Quiktune 1000