Just wondering where one can get a plate to hold a MW in place or what these things are called? My rig as a plate that fit around the MW (not the OEM one from Coachmen) with flange to hold the MW with screws, has ventilation louvres and is fastened by screws into the cabinet. The piece appears to be specifically manufactured to fit (finish/covering for one) and not a custom job.
Like to replace the MW with the one in our house which is smaller (at least 2" narrower and an inch shorter.