Too tall to store in that space but could store elsewhere when not in use (behind benchseat). Reverse the probes and take a second resistance. Take a resistance measurement between each of the magnetron's terminals by touching each probe to one terminal each. Set your ohmmeter to the lowest resistance scale. products arent available, a microwave could conceivably replace almost all of the. TEST 1: Locate your magnetron and label each of the wires attached to it so that you know which wires are to be replaced where. If must have a microwave, there is a small Whirlpool rounded cube microwave. The actual microwave radiation itself is generated by a magnetron. Use the space for storage, like a toaster oven (have to remove when in use and cooldown before storing).
Wavebox might fit without carrying handle? Manual Transmission Wave Box Applicable to Mitsubishi Hafei Horse Racing BYD F3. Haier, Danby, Proctor-Silex, Westinghouse, and other brands have small 0.6 cu ft microwaves which are slightly too big for cabinet opening (but may fit if feet or cabinet opening is enlarged). Possible searches for "micro" or "mini" or "compact" or "small" or "smallest" microwave brands might include Haier, Daewoo (a QT1 240V version used in Europe), and portable Wavebox (not good reviews).
If can find a microwave which fits the interior space, can enlarge the cabinet opening (get rid of folddown cabinet door). There may be Westy owners who do not use and may be willing to sell. Consider the dimensions without feet or handles (every little bit helps, replace feet afterwards). Warm reminder : Microwave oven magnetron 2M213-240GP product is original disassemble, couplers 7-8 into a new, after ultrasonic and special washing liquid.
The cabinet opening of about 18" x 10" (curved corners) restricts the possibilities. Unfortunately, microwave was discontinued years ago and no replacement microwave with the proper dimensions to fit through the cabinet opening and air space is probably available. The original microwave was either an Origo or Tappan, about 0.5 cu ft and 550/600 watts or so (different name brands, same microwave).