As for being forced to use your right hand. Yes, unfortunately that happened a lot (I sincerely don't hope any more). I have met a lot of older people (patients), who told me they were forced to write with their right hand in school. Consequently they write with their right hand to this day, but usually do everything else with their dominant, left, hand. Usually there wasn't as much pressure on them to do other things with their right hand.
All this to say, that if Jack peels potatoes with his right hand, I would imagine he's right-handed.
That was before I checked the shaving scene that Chrissi mentioned. I would imagine shaving with your wrong hand is very difficult, and would probably not have been forced upon you. Maybe our Jake actually is ambidexter?
And, to answer your question Chrissi: no, Jack is not who I had in mind.