Hey:
I found this new surplus one online if you are interested:
https://www.johnsonssurplus.com/products/half-time-microwave-conventional-oven-stainless-steel?currency=USD&variant=39603520012397&utm_medium=cpc&utm_source=google&utm_campaign=Google Shopping&matchtype=&network=g&device=c&keyword=&campaign=909371242&adgroup=pla-293946777986&gclid=CjwKCAjwndCKBhAkEiwAgSDKQR1FEaJdWTdSFV1Rp4pdgSWv3EKQk3RPxSaxIhV6sS06zzzuXMevExoCei0QAvD_BwE
On edit: The Halftime Oven was originally designed to be freestanding on a countertop, and Midwest Sales had an operation going to add a squirrel cage blower on the outside top rear for adequate cooling in an enclosed cabinet installation. You should be able to move this cooling fan from your old broken Halftime Oven to the new one, if you get one.
Otherwise. get the outside dimensions of your old one, and then do a websearch for: " convection microwave xx inches high xx inches wide xx inches deep ' or just: " microwave oven xx inches high xx inches wide xx inches deep " I found a Sharp microwave oven to replace my 2nd failed Halftime oven this way. I added a squirrel cage blower (found on E-Bay) on the top back for proper ventilation within a cabinet.
Many of the microwave oven parts are generic like latches, turntables, magnetrons, etc. A knowledgeable appliance servicer might know the generic source for the parts you need. If you go see the servicers, take the old (broken?) parts with you, or take pictures on your cellphone of them.