Nicely done, with handsome results! I'll be interested to learn how well the Renew-Point works without an air channel back into the convertor. I tinkered with this concept awhile back, and it always vapor-locked on me. I ended up ditching the nipple and plug entirely and making the pen an eyedropper filler instead; that worked *very* well.
So far I haven't noticed any problems, but my writing habits are far from normal: I use the pen to make a few notes, then set it down and program some more, then make another note, and so on. It's conceivable this allows it to avoid locking.
The first pen I made to take Renew-Points is a bulb-filler. It writes a very wet line (using the 2442 stub that I've got in there at the moment) but the volume of ink it holds (compared to a converter) means it keeps going and going and going.
Shawn Newton (watch_art) told me that when he made an eye-dropper he found it had a tendency to flood, so I was going to avoid that route ... but you found it worked very well, so maybe I'll try it after all. They are a lot less challenging than any other ink supply!
I wish I could find a source for very thin o-rings, the standard dimensions are way too fat and look ugly. I know they exist (I have a couple of the Noodler give-aways that use them) but none of my searches have been fruitful.