New to me Crown Graphic with 101 Ektar, Synchro-Rapid 800.

Shutter cocking works, but release lever does not.

I have it off camera, on the lensboard, for inspection.

Notes:
- flash synch is set to "M" position - I thought I read something about flash synch being problem-prone on these shutters(?)
- if I give the assembly a good slap in the palm of my hand (very technical), the cocked shutter then trips.

Any advice?

Odd timing... I finally found Ronsonoil at local shop, the other day!

EDIT: I did find this shutter series repair manual, but i need a few pointers before digging into that - mostly the don'ts!

For the "Ronsonol soak," remove front and rear lens elements and douse (but don't drown!) the innards with the Ronsonol, working the shutter mechanism the while. Allow time for the works to dry (Ronsonol, AKA naphtha, evaporates rather quickly; I'd give it a half-hour just to be safe). Re-install lenses. Hopefully this will loosen up the old lubricant and get you back in business. Let us know.

There should be a middle element in there, correct?

If this shutter is not repairable, that would be a shame because the Ektar lens has a decent reputation, and is in great condition.

Whatever glass is in there, remove it.

For shutter service, try these folks: http://www.flutotscamerarepair.com

I would exercise caution in using the "Ronsonol soak". It has been noted in other postings on this site that the result of this may be simply to distribute dirt throughout the shutter, putting it in places where you do not want it, in particular on the shutter and diaphragm blades. It may also attack plastic or rubber components in the shutter. And if the problem is mechanical (bent or worn levers or a missing spring) rather than simply dried out lubricant, it will not solve it.

I've not worked on a Synchro-Rapid myself, but I would suggest taking the cover plate off and operating the mechanism to see if you can localize the problem first. If you can identify the sticking component, it will at least allow you to concentrate the Ronsonol there rather than applying it everywhere.