50mm Solex's on Ebay

I thought I'd put this here since 50's are for the most part a "race only" item. I emailed him asking if they were Solex/Mikuni's, or strictly Solex. He replied with the following:

Theses are made by solex before Mikuni took over. These were made when Solex and Mikuni first started merging. They are cast Solex made in Japan

Ebay auction here

The N42 head is also included. I wonder what Mikuni parts, such as jets, will transfer over?