Hello gshoemate- Finding custom size frames for off sized prints can be a problem. We own a custom frame shop on Long Island and usually have a huge build up of "knock outs, or windows" from matting other jobs. Unfortunately we throw away a great deal of mats that would be ideal for your needs. Might I suggest that you go to any store and buy an 8 x 10 frame that you like and then send me a large self addressed envelope with stamps, and I'd be happy to send you, at no charge, a few mats cut to 8 x 10 with an opening 5 3/4 x 7 3/4 to hold your print. Tell me your color preferences. I just hate throwing away perfectly good material when there is someone who could use it. If you have any questions, either post or PM me.
Sandra