I have a two coin controls S10 coin mechs.
I purchase all my coin mech spare parts from swallow amusements, they have quite a lot of spare parts for arcade cabs. Ordering process is via a donate button on a payment page but you will need to contact them first to get a price inc p&p. Guy called Stephen there, seems very helpful, I just ordered some equipment wire from them this morning.
They have the new red rejector buttons for the S10, these may fit?
On a similar note, does anyone know if rejector buttons can be sourced for the coin controls S10 that are clear instead of red?