I am looking for the following doors for crystal regulators with or without glass.
2 doors - 5-1/8" x 7-7/8"
2 doors - 4-5/8" x 7-7/8"
1 door - 4-1/4" x 6-15/16"
2 doors - 4-13/16" x 8-7/16"
Thank you for your anticipated help.
There are guys on the big auction site that will cut sheet brass up to 1/4 inch thick to the dimensions you specify and charge by the square inch.
If you had them cut long strips, a local machinist should be able to clean-up the shear-cut edges and put in a channel. You might even have them shave the ends to make your mitres.
You could do it by hand; But, it'd probably not look great, once assembled.