The Modern Bajaj Chetak Rides On
 
Picture
The complete Stella tail light unit can be swapped out for the Bajaj Chetak tail light unit. New holes must be drilled in the body and a rubber gasket can be built up to fit it properly.  

 
Picture
When the Bajaj Chetak H4 headlight lens has cracked, some riders have replaced the whole unit with a car sealed beam unit like the Volvo 240's:  GE model GELHE54697

 
The Bajaj lightbulb for the Chetak is unique (wider tabs) but a H4-35W 
or H4-55W or H4-60W will fit.

The Modern Bajaj Chetak Rides On The Modern Bajaj Chetak Rides On