Thanks for the info, particularly the section regarding the SR engine being the same! This might save one (if not both) of the bikes. I know that the '81 SR was running before but I did not want to spend as much money as was quoted (then) for the redo. If I could get one working, I would prefer the Urban Express, just because I like "bigger" and more durable and stable bikes than the smaller versions. (It's why I am a rare soul in my town who actually WANTS to redo his old Magnum rather than the Maxi).
And, no, sorry, I haven't gotten to the carb yet, but you are among the mechanincs who have said that's where they'd start also. My old guy here recommended same. An upcoming project.
Two other questions: Where can I get a rear brake cable, assuming I actually get it running? And, where is the VIN plate?!!! I looked where I expected it to be based on other Hondas (front fork below handlebars) and found nothing. I looked all over for ANYTHING and found nothing. Is it under some plastic cover plate or what?