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These cool little pedals were sold in the 1990s-2000s and are named after diner food. I have several and have done some work on them.
The pots on these pedals have small silver knobs which must be removed to take the pedal apart.
After they have been removed once, they will not stay in reliably when reinstalled. This is why a lot of the pedals you see for sale have no knobs. The pots are by Bourns, but the shafts do not match currently available Bourns pots. I think Danelectro might have taken the normal Bourns pots, cut the shafts off flush with the pot's bushing, then machined plus-shaped holes into the remaining plastic. Their small knobs have a protrusion from the bottom that looks like the tip of a Phillips screwdriver. This is inserted into the plus-shaped hole in the shaft. It is near impossible to find replacement knobs.
What I have done is to replace the pots with normal Bourns pots, then attached small silver knobs which fit a normal pot shaft. I used pots from Bourns' "PTV09A" series that have 20mm-long knurled shafts with 18 teeth. The part numbers for these pots look like...
...where ???? is a letter and 3 numbers indicating the pot taper and value. Most of them are linear ("B???"), but some are audio taper ("A???") or reverse log taper ("C???"). The "???" is a 3 digit pot value with 2 digits and an exponent, i.e. "104" = 10 x 10^4 = 100K ohms.
The data sheet for this series of pots
I found some knobs on Ebay which perfectly fit these pots and are small enough not to cover up the knob labels when installed. Apparently they are called Uxcell A19091600ux0548, but this manufacturer and part number are often not shown in the Ebay listings. Typical mystery parts from China. I could not find any knobs like this from a more known manufacturer. If you know of any, let me know!
Here is one listing on Ebay. If you select:
Hole: Knurled Shaft 6mm
Knob Size: TYPE I:10x10mm
...this will give you the correct knob.
I also ordered some from this Ebay listing, and they are exactly the same knobs.
Here's how a T-Bone Distortion pedal looks with the pots replaced and knobs added: