After 10+ years of reliable service, the AC/Delco starter in my 69 has started acting up. About one time out of every 10, you turn the key and nothing happens. When this happens, I can take a long screwdriver and touch the large post on the solenoid over to the small one and jump the starter over one revolution or so. I can then get in the car and start it with the key normally. Before I go spend the money to buy one, is it safe to assume this is bad solenoid?

No, bad ground. I would check them all. I haven't seen one go bad in some time even tho I have people tell me it was bad. I have three sitting her all new and all good . Bad ground all the time it seems or bad regulator not charging the battery and being run longer for the time need to recharge it

Thanks for the idea, I'll check the grounds.

Run a drivers side solid steel motor mount...helps out those pesky grounds ;)