You've done well with difficult to source spare top SR and it's tidied up a treat. Hope you can find the cover and a better catcher one day. Keep looking. They're out there. You don't have to use that exact catcher.
Nearly all thumblatch designs will work on that base casting, except from any self propelled models, the Victa Twin or the Victa Compact. The original shape like yours would be the most desirable of course.
Main thing is you got what you have in sound order. The mower itself looks in great condition!
