Hi Peter, that is a 207cc Tecumseh Ultima. It was built on the 262nd day of 1996. I personally love the grunt these engines have but yes, they are a relatively odd ball motot. My old man has one and it's got oodles of power and runs pretty much the same as a Briggs Quantum.
I have not done much work on these before other than the usual service items but i can tell you this much.
the "Hi Zone" filter is a standard Victa long paper type cartridge, Plug is a J19LM, the missing plate is just a metal cover which you could make out of some 16 guage plate. It just bolts onto the two holes on the little plate above the throttle linkage. The cover wouldn't need to be a perfect fit, just big enough to mount to the 2 holes and enough material on the back enf to support the cable clamp.
Do the usual tests and see if it's worth proceeding with the project.
