I'd get it under contract only because of the upside you mentioned, but would go in with my eyes open that as those become vacant there's a good chance it will make more sense to junk them than fix them. I would not want to rehab 1960's homes unless it's very inexpensive repair work.
Also if you do want to replace these at some point make sure the size of the lots will handle what you would want to replace with (e.g. 16x80's for example), and also realize as you replace these you're also going to have to upgrade to 200 amp electrical panels form the 50's that are probably in there now.
Confirm the state will allow the rent / utility increases you're planning. Florida for example has some laws that would make this more difficult.