Your Bultaco TSS replica and all AJR TSS 350 spare parts are available ON-LINE.
Also special spare parts for competition Bultaco.
Selector shaft replace Bultaco 49.13-015 for use with San Antonio 2 engines with right output and using the intermediate cover desing (see pictures)
Other options:
B2313015 long shaft for right output with round design case
B4913015 short shaft for right output with intermediate design case
B11213015 shaft for output on both sides with modern design case