Thanks for your thoughts gents.
Bill,
After sitting all night with the puller on and with Liquid Wrench trying to work (on the dynamo sprocket, that is), I went out this morning and whacked the end of the puller. No go. I didn't try to kill it with the hammer because it seems this process actually gets the screw and claws going in the same direction, to little affect.
Morris,
Without stepping into the garage, this minute, to check for sure, I doubt there is adequate flatlands on the sprocket for the holes. If there is, I might go that route.
Muskrat,
Now you're making me think I didn't hit it hard enough or heat it hot enough. The 1/8" gap made when trying to pull out the cover is enough to see the idler can slide in and out a tiny bit when pulling on the sprocket spindle. So, next thing I try might be to wedge the cover open, block behind the cover and sprocket and then whack the end of the spindle (nut on, or wood block). Yes riding is better than fighting, but it was rainy early yesterday and I'm a rain wimp. Besides, did you notice the time of my last post? Midnight.
Dutch,
Since I'm responding in sequence, it seems like I just described to Muskrat what you suggested. Great minds think alike (and, occasionally, mine comes along for the ride). This will definitely be my next approach.
Bill (again),
I'm wondering if any kind of deformation wouldn't actually help when it comes to breaking the hold of rust or corrosion.
Nigeyp,
Hadn't heard that one, or thought of it, but think it unlikely to overcome 20 or 30 years of rust/corrosion. Nevertheless, everything is still on the menu until the job is done.
Thanks again guys. Other thoughts still appreciated. I'll let you know what happens, but it may not be today.
Richard L.