Engine origin

Sorting through my spare engine cases , looking for a suitable candidate to build the Quattrini or similar.
Never noticed before but have a particular chaincase stamped in two places with differing numbers (1st place Normal position, and 2nd place on the r/h side engine mount slope),and curious as to its origin of manufacture. The cylinder head is marked 150 but no CC identification on the case.
Would appreciate some info …...Attached photos.
Regards
https://i.postimg.cc/0ynGS82Z/IMG-20201028-213858.jpg
https://i.postimg.cc/255QFP1Y/IMG-20201028-214053.jpg
Never noticed before but have a particular chaincase stamped in two places with differing numbers (1st place Normal position, and 2nd place on the r/h side engine mount slope),and curious as to its origin of manufacture. The cylinder head is marked 150 but no CC identification on the case.
Would appreciate some info …...Attached photos.
Regards
https://i.postimg.cc/0ynGS82Z/IMG-20201028-213858.jpg
https://i.postimg.cc/255QFP1Y/IMG-20201028-214053.jpg