I use the Navcon silencers in my HW-19 and they work better than the sorbothane ones I used before that. They have an aluminum base threaded for the same thread that held the springs. I used some short threaded studs to mount them into the frame and could easily adjust height. They also don't ooze goop and distort like the sorbothane did. Unfortunately, I think they are no longer available. I have occasionally searched for some more but no love. Herbies may be your best bet.
