I am sorry, I cannot help with useful confirmed information, but here is a picture of a Polish cockpit claimed be a MiG-21PF with the gunsight and a similarly looking, but still not identical additional panel on top of it.
Then, if I may re-post a picture of a MiG-21PFM cockpit, shared earlier by Gepard, where that same panel is clearly visible with the labelling mostly readable:
I can see a selector switch to the left, which maybe allows different modes of the gunsight to be selected depending on the type of weapon to be fired/dropped.
I can read пушка (gun), then РС which stands for unguided missiles, the third one is mostly unreadable and I have no clue, while the last one says бомбы (bombs).
Then the text above the 3 buttons says перезарядка (recharge/reload) and according to AI these 3 buttons are used to activate a pneumatic/pyro charge, which in case of jam help clear it and the gun is reloaded. Apparently this can be done only 3 times in a flight.
The panel in your picture is similar in that it has the 3 knobs and text above probably says перезарядка, but the selector switch is not present.
Based on the history of that ex-Hungarian MiG-21PF board 503, I would question the extent to which its cockpit could be used as final reference.
https://www.rafmuseum.org.uk/documents/collections/X003-6783-MiG21PF.pdf
The document in the above link says the aircraft was purchased from the HuAF to be used in a James Bond movie, which means before it was handed over to the movie production, it was most certainly stripped of anything weapons use related, such as the gunsight for example. Then it was brought to the UK, where it was assembled by Hungarian technicians in airworthy condition.
Lastly, as far as I know, the MiG-21PF could not be equipped with a GP-9 gunpod, which was introduced with later variants such as the MiG-21PFS and the MiG-21PFM, so I am curious as to why would there be such a panel with buttons to cleat a jam and reload a gun in the MiG-21PF cockpit.