hmmm, those springs do not look like they have enough "tension", but I assume you ran the dist on your machine.
If you want to try some nos corvair dist springs (delco 6 cyl), I can send you a pair. We can "discuss" which "corvair engine" is a "good fit".
The distributor springs are supposed to be "slack" when the advance counterweights are static. Lots of slop. I have all kinds of delco, Holley/motorcraft, and other distributor advance springs to chose from. The delco "curve tuning" kits are readily available here locally, I keep 'em in stock to use the pieces for all kinds of stuff, some of the delco springs I use in Holley distributors currently. The particular diameter springs I chose allow sufficient clearance under the breaker plate to prevent interference when in rotation. That is what was wrong with the unit when I found it...someone had bent the shit out of the breaker plate trying to make clearance, the springs that were in it were too large in od and were not oem!
So...the mechanical advance had not been operational in ages no doubt, and the distributor was locked down since the vacuum advance was inop also. In order to allow the engine to crank without kicking back and breaking the starter drive, the timing was greatly retarded and had no form of operational advance system.
Keep in mind, while these units are a very early form of delco remy sparker, they have little in common with the delco distributors supplied post-wwii, particularly in their very compact size.
The externally-rotated advance system was used on many IH six banger motors up through the late 50's though. Most engines/vehicles from the teens through the late 30's used a mechanical spark advance controlled from a lever mounted on the steering column...retard the spark to start the motor, then advance the spark to run, the advance lever was positioned based upon the quality (octane rating) of the particular fuel being burned. For burning kerosene or "drip gas", ya could not advance the spark control at all! The willys-overland/ihc motor was somewhat unique for the times in that it had a vacuum advance system incorporated instead of a manual control lever.
I don't have a distributor machine to test run these sparkers, I do it with the engine running and using a tach and dial-back timing light to test the advance curve.