I commuted for a year on a Huffy 3 speed I paid $25 for. I could have paid over $1000 for a Pashley that would have been a worse bike for the job...
Everyone assumes that just because it's not a bike built for competition, it must not be worth using, it's a silly, biased viewpoint. I don't think the OP is planning on doing any time trials with his All-Pro - so there's no real reason he shouldn't repair the bike and ride it if he wants to. It should be perfectly suited to toodling round the neighborhood or going to the post office as any bike costing five times as much.