Thanks guys! All I needed was just the little clue. What worked for me (the second time!) was to only remove the shift lever, 4 main nuts, 3 hex screws, clutch cable, and speedo drive. Leave in place the kickstart lever and the funny little nut on the left, both of which come off with the cover. Install spring, wind the kickstart lever back around to preload, and let the clutch lever hold it in place. Slide trans cover in place, and when you hit a stop allow the kickstart lever to come back around. Lightly tap the cover home, install two or three of the nuts to hold cover in place, and push down lever with your hand or foot (plugs out). If it pops back up, button it down. Simple once you get the clue on how to preload the spring. For me it was not obvious.
Interesting I have ridden two A10s since the mid-60s, both over 100k miles. This is the second one. Never had a spring break before, though I understand it is common failure.
Again thank you all for your help.

1963 BSA Rocket Goldstar, 1969 Triumph Tiger, 1969 Norton Commando, 2017 Yamaha FZ07, 1955 Ford Thunderbird