It has been considerable time, but I thought I'd update this post, considering other events unfolding rather quickly, which would seal the fate of this project.
When I left off, I did the welding repairs and was about to test fit components when I encountered another set-back... The head tube was worn out. I had a 1" headset in my stash of parts and I went about to test fit it, it just dropped in and wobbled! Normally, cups are sized 0.2mm bigger for an interference fit but it was now undersized. Sigh. I started to consider going to oversized 1" headsets (at 30.4mm), but then, they are very hard to come by and if the head tube needed to be reamed for that, who has 30.4mm reamers? I also thought maybe I should just use epoxy and glue the cups in, but then, how effective will that be long-term?
I put the frame aside and moved onto other projects.
I suppose the stars were aligned and I came across another Cannondale project to replace this one. I'll be posting about that soon. It's a good one!
I have gone ahead and painted this frame and it will be assembled and decalled. It is essentially a wall-hanger now and I am considering donating it to either a local bike museum (if they'll take it), or another far-away museum. Or if an individual wants to hang it on their wall... Either way, I don't consider this rideable. It served someone well and I'm sure they had fun riding it, but it's time is done.