while i don't specifically know the value of the damaged part (i'm sure I could find a schematic and look it up...) but you can place an ohmmeter between the 2 outside legs of the pot to find (approximately) it's value.
if you wish to replace them, the values of the pots are printed right there on the front of them.
the value is decoded as AAB with AA being a value in ohms.... and B being how many powers to raise this number
for instance "103" would be 10 and 3 zeros. so 10 000 ohms or 10K ohms..so on and so forth.
i believe the wattage on those small pots is 125 milliwatts and of the carbon variety.
that said, it looks like the wiper contact in your damaged pot appears fine. it probably still functions okay. you would just have to insert a tiny flat blade screwdriver in there to turn it. (the plastic bit that has come out just makes this easier to adjust.) you can actually buy trimmer pots without all the extra stuff on them, and they are often called "skeleton" timmers. used internally some something that needs to be set, then never touched again, they can be had for fractions of a cent each.
i'm not sure if you could find an EXACT replacement for that style of pot (as these parts become obsolete fairly fast as the companies who make them come and go), but something like this.......
https://www.ebay.com/itm/10pcs-WH06-1A-502-Side-Adjust-Carbon-Track-Trimmer-POT-1-Turn-5K-Ohm/400988400436?hash=item5d5cc56b34:g:8LQAAOSw0JpV5d-~is much more common and should slot into its place without issue...you just have to order the proper values.
search for "right angle carbon trimmer pot _______"(the value you need such ad 10K or 200)