Pure `find`:
find . -regex '\.[^.]*1\|.*1\.[^.]*'
This will match `ver1` and `ver1.txt` and `file1.ver1.txt`, but **not** `file1.ver2.txt`. If you want to match that too:
find . -regex '\.[^.]*1\|.*1\..*'
You must run these commands inside searched directory, `find somepath ...` whouldn't work, as regex match whole path.