Here's another option
Custom RealDrum Solos\Hits Mac\Win you can also create an SFZ instrument from the same realdrums and use it in Sforzando VSTi on the midi track you can mute the realdrums on the bar/s with the shots/holds then add the midi notes you need in the piano roll on the bar/s that you need the custom shots/holds, then un-mute the realdrums after the shots/holds.
You can try it first with the PG Library in Sforzando > Drums > Rock Kit.
1. Use F5 to mute the drum track where the shots are.
2. Load Sforzando vst into a midi track.
3. In the Piano Roll view in the same midi track, hold the shift+ctrl and draw in a note, move the note up/down until you get the hit you want (make sure you have ASIO or MME Always On in the Driver Settings), draw in more notes if need be.
4. Use F5 to un-mute the drum track after the shots.
You never know the Rock Kit may be the same kit the surf drums were recorded on in the PG studio. You have some FX in the Sforzando GUI to adjust the sound to match the RealDrums or you can add some FX after Sforzando. You can copy and paste the midi shots if you need them again.