Pablo, it is a great idea to revive our old request to "introduce" ourselves.
I also will ask if you did search our Romania (Bessarabia) database? There are a lot of hits on CHAMUDIS (KHAMUDIS - that is the same).
For example. Tatar-Bunary was not a very large place, it is clear that this is your relative:
and one more:
There are also many records with this surname, but not in Tatar-Bunary, but in Akkerman. It is possible that some registrations, like for Merchants could be done in that small town, but people were registered in Akkerman.
Also, please when you introduce what you are researching, in addition to Last name, write first name, and very important - dates people lived in town (approximate date is OK too).
I am looking forward to hear more introductions from our members, and please help each other if you can... and if so, you would be helped too.
All the best,