Well it seems there is more than one opinion on what constitutes good
and bad old junk.  I think that the bicone switches are great.  Most
people don't know that they exist because they are only starting to
fail now after 70 years of neglected service. (I have replaced numerous
modern switches after only a couple years of use.) They may be crude
and badly engineered by todays standards but they last and are
repairable. I also like the switches in my land rover which can be
disassembled cleaned and lubed using only a tire iron and some bear
grease in less time than it takes to pick up your cellular phone and
call AAA, but some people prefer the modern easy approach.  They are
snap acting wiping switches and do as well to suppress arcing as modern
switches. When they fail it is usually a broken spring which can be
easily fixed or worn contacts which can usually be dressed.  Some of
the springs are "snake swallowing its tail" which are inpossible to
make without spring winding equiptment but others are just short
springs looped together endloop to endloop.  Springs like these can be
found in old typewriters or in places that repair them.  The loop to
loop seems to be a fine replacemnet for the other type.  Make sure to
resurface the bicone and lube with an non conductive (eg. silicone)
grease.  When the contacts fail it probably means that the switch has
had a lot of use, or that the load is too high.  Before putting it back
in service check the motor load and preferably switch the current with
an ssr or other relay. Even just barely there contacts will opperate an
ssr. You could even replace the spring contacts with solid metal to
switch milliamps.