There are a number of 150 combos some have effects and some don't. If yours has the basic reverb and trem, it should use a standard two button switch with a stereo 1/4" plug connector.
As far as I remember, the original ones were round diecast domes, with two standard push on, push off switches.
I see them on eBay pretty regularly, they usually seem to go for $60-$70. I'd love to have one for my combos, but can't justify spending 1/2 to 1/3 what I paid for the amp on just a footswitch
I see the single-button ones, they go for a LOT less (like $10-$20)
But yeah, functionally, most any 2-button passive switch with a TRS plug should do it.