Are you searching for pushencoders? I have the right bourns encoders and quite a few spare, bought from mouser.
PEC12R-4030F-S0024
These Bourns push encoders work well for the upper row. A bit less resistance than the original, feels great.
Hi
It could also be a Bourns PEC11
From the data sheet...PEC11- 4 0 20 F - S 0012
PEC11 = Model4 = PC Pin Horizontal/ Rear facing
0 = Detent option0 No Detents1 28 Detents (18 pulses)
2 24 Detents (12, 24)3 12 Detents (12)
20= Shaft length mm 15,20,25,30
F= Shaft style (F for Flattened, K for Knurled)
S = switch , N = no switch0012 = Resolution (number of pulses. 0012, 0018, 0024)
Hope this helpsRoyce