sikpupy, please post pictures of the mower and its old engine. Are you looking for:
1. Any engine that will suit the mower well?
2. An engine the same as the old one?
3. The "best" engine (in somebody's opinion) for the mower?
Also, what was the old engine, and what went wrong with it? The Model 33 seems to have been built with two or three different engines over the years, and some of them do not die easily - most faults are not difficult to fix.
You might enjoy the pictures of a restored Model 33 in this thread:
https://www.outdoorking-forum.com.au/forum/ubbthreads.php?ubb=showflat&Number=16085
