I buyed some original 820pf poly caps from Best Electronics.
https://www.best-electronics-ca.com/2600_Tech_Tips.htm (search for "820pf" on the page to find it)
I took the opportunity to buy some others spares (4th gen CX40 Gold PCBs, original PAL TIAs and RIOT Chips, switches, sockets amongst other things...) in order to make shipping costs profitable (i'm European too).
I know ... Best Electronics web site can be a little disturbing, but with the help of google you will find any original spare you want. After all, Bradley's site is way newer than ours good old VCS consoles