G&P Scorpion R500 Question

[1983gl1100a]

Hello all! A newbie here so please be gentle! I have inherited a G&P Scorpion R500 (not R500S) that is missing the tail cap. It has the remote pressure switch so I know it works. I know it is not a new flash light but would like to get a tail cap (G&P or otherwise) for it. I find all kinds of tail caps on ebay but none seems to refernece fitment to the R500.
Can anyone assist in recommending a replacement tail cap? Again OEM or otherwise?
Thank you for your time!

 

[Fusion_m8]

The G&P R500 tailcap is Surefire C-series compatible. You can use a Surefire 6P tailcap or any of the new Solarforce tailcaps like the L2-S3, S6, S7, S8, S9, S10 or S11 on ebay rated to handle 3amps.