This followup is just a quick fix tip for the benefit of others who may come along to this thread in future also with a front brake light switch whose flimsy plastic retaining locking tab "ears" have broken off and so no longer hold the switch assembly properly in the brake's hand lever housing such that the spring-loaded switch at its end operates.
As described in an earlier posting to this thread, I did purchase a pair of replacement switch assemblies, and although it has been nearly four months since I received them, I have not even bothered to mount one of them. I may likely
never bother doing so. This is because the simple "temporary" fix I did while awaiting delivery of a replacement from India seems to still be working perfectly and hasn't budged in several thousand miles.
It turns out that one of those little standard screws used in PCs to secure hard drives and other hardware in the case known as
PC Mounting Computer Screws M3 x 1/4in Long Standoff will hold that brake switch right where it ought to be just fine and keep it there.
I simply lined up the switch assembly inside the front brake lever housing such that operation of the brake lever activated the switch and brake light properly, put a couple of drops of
generic Loctite onto the screw's threads and also into the top square hole in the brake lever housing into which one of the two flimsy switch assembly retaining "ears" normally clips from within, screwed the M3 screw down gently until it met and gently held the switch assembly, and Presto! No problem since. These little M3 screws are just about 2.9mm thick at the threads, and will very gently "self-tap" nicely into that square hole. Don't over-torque it! A very light touch indeed is needed here.
If you've got some old PC laying around, you've already got a lifetime supply of these screws. Toss one into your tool pouch now. Those original switch assemblies are
really flimsy. Frankly, I think this fix is probably
far more secure than that original flakey assembly.
If you can't be bothered cannibalizing your dusty old Pentium, and just want one of these M3 screws for your tool pouch, I've got plenty. If you send me a self-addressed stamped envelope containing a note that simply reads
"Screw me!", I'll be only too happy to oblige. Just email or PM me for my mailing address.