Ok it's done. Cleetus's point was well made, and I had givwn the entire guts a good blow out and then lube before I inadvertantly broke the ejector hook.
I agree, given this early mechanism, it's always going to be harder to open when decocked. This was something more. I could barely even open the barrel!
So yesterday I got my new parts, replaced the ejector hook (a brand new, perfect fit reproduction from Numrich), and then got to work on the ejector spring.
I have had other barrels which required a small amount of spring trimming, but this one is extreme. I trimmed one down quite a bit and realized the extractor was still getting stopped out beyond the flush threshold of the breech.
So I ground about 1/16 off of the spring starter pin, grabbed a fresh spring, and trimmed again slowly until it felt like the right tension.
Took her outside and fired, then opened...all good.
Now, I would not have thought that that starter pin was long enough to get fully stopped out between the hook and extractor to not leave enough room for the extractor to seat flush when closed. But this simply must have been the case.
So...FIXED.
New ejector hook, new [trimmed] ejector spring, and spring starter pin trimmed 1/16.
Sentry44