That catcher on the FleaBay mower isn't in all that good condition; it's had a couple of 'tenant improvement' frown repairs.
Still not too bad for a ~50 year old steel catcher, though!

The low arch Mayfair chassis changed very little over its manufacturing run, so I'd be fairly sure that the later plastic 'Model 15' catcher would fit your mower, and be easier to find than the tin one - this one, shown in a recent thread [Pic credit: seanw]
[Linked Image]

An older Victa 125 mower is about as durable as it gets - they are nearly impossible to wear out, barring user idiocies like 'straight-fuelling' [not adding oil to the fuel], which happens to them all too often, these days.

For a 'regular use' mower, I would strongly recommend fitting a paper element air filter unit. Not hard to pick up secondhand from tip shops, or probably your local shop who gave you the mower. Won't affect the mixture appreciably; we used to fit the NLA AF07381A short filter to the early models in the 1970's.
This one:
[Linked Image]

Cheers,
Gadge

"ODK Mods can explain it to you, but they can't understand it for you..."

"Crazy can be medicated, ignorance can be educated - but there is no cure for stupid..."