I've learned to trim the bogus filters to make them work after I got about
half a dozen of them on ebay. Same basic box is used on the 140s so this
is applicable to them also. I trim about 1/4" all the way around the outside
of the foam rubber periphery and it seems to work fairly well.

My 69 164 has a mechanical switch on the shank of the brake pedal, and I
am pretty sure my 73 164 did also. Want me to check and see if I can find
one in my rodentine culch heap? The bracket is quite simple, and the switch
is similar in principle (different in construction) to the dome light switch
on the door frame.
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma