In my opinion, Jim is lazy, but not dumb. It doesn’t sound like you guys have been very good at formalizing things under the company and Jim knows that and has positioned himself quietly as the one with all the power.
Setting my analysis of Jim’s character aside, I think your best bet is to not demand a thing, just keep your already agreed to equity you have documentation on and walk away. The reason being you don’t want to give Jim the chance for a new document to muddy things up more in case of later litigation.
He may restructure or do some sneaky thing to make himself feel as though he’s bested you, but the likelihood whatever is made is going to make a huge amount of money is slim (especially with what I see as severely amateur behavior here coupled with a lacking in ethics). He’ll have a hell of a time raising any funding either way if investors do their due diligence.
If it does succeed sometime in the future, send the whole file to a decent attorney and let them do their jobs then.
In the meantime, just understand the tactics he’s employed and do think defensively, preserving what you do have now. Then store it in case you need it later. After that, move on with your life and forget about it.
I’d probably remove Jim from your life though. Every comment I’ve read from you about him has had the between the lines description that his behavior has never been in your best interest. He doesn’t care about you at all.