Looking for a source of gears that are
- 1/2 wide (so far only found 3/8")
- 20 diametral pitch
- 14.5 deg pressure angle
as per gears used in AM Super Shifter transmissions
http://wcproducts.net/gears-20-dp/
Should be what you are looking for but, they are .400 and .600 in with.
Wasn’t aware of that source. Thanks. I better go measure my gear 
SDP/SI (Stock Drive Products/Sterling Instrument) has gear stock from which you could turn any custom face width. (Other diameters available too.) Of course, their online ordering system continues to be horribly broken (and irreconcilable with their phone/mail ordering system), and their shipping to Canada is typically UPS with all of the associated brokerage fee headaches.
Linn Gear also sells 20 pitch, 14.5° pressure angle gears, but they apparently don’t have an online catalogue.
Thanks for info. Unfortunately SDP gear stock has huge holes in selection between 30 and 40 (only have 30, 35 & 40). My spreadsheet says we need in the range of 36,37 & 38. I’ve asked AM where they get theirs made.
Will definitely try Linn!
Martin Gear and Sprocket [strike]has them too (page G-35), in 30, 32, 35, 36 & 40 teeth.[/strike] (Edit: No, they’re 20° pressure angle.) They have hubs, but that can be dealt with.
I believe Canadian Bearings (and probably BDI) can bring in Martin gears locally.