After seeing the videos one can definitely say there is a very well thought of RPG system implemented. It resembles very much Wizardry, which I like a lot. There should be more games like it.
I can see a huge problem though if this is to be distributed for iOS. The buttons are just too small to be touched comfortable. And there are lots of these small buttons. All of them are required for the micromanagement, but this just won't do for the small touchscreens. No one will playthis game with a pencil. Grimoire can only be a PC game.
If you insist on porting it to iOS I'm afraid you'd need to purge a lot and simplify the RPG system, basically a complete overhaul, a rewrite with an all new interface featuring big buttons, less micromanagement. This would probably kill what the initial game was meant to be. There are some dungeon crawlers released for iOS, and they all have much reduced interface e.g. google for "Undercroft".
If you worked 18 years on it, I would try to finish it and release it. That's one thing I always tried myself: what has been started must be ended. You may and should need to cut lots of the features you initially wanted in the game, in order to finish it, but you will be proud of it. It's a fact that game development is a very time consuming and challenging task, no matter how simple the game looks like. An RPG isn't simple.
I suggest either to finish it by yourself and shape the game in a way it can be released (by that you may need to remove certain areas or maps which are not yet populated etc.) or to hire additional people working on it.
I don't know if the latter one will work. Poetential artists or programmers are maybe turned off by the fact, that this dungeon crawler style is at least 10 years too old. I don't think there exists a big enough fanbase for it anymore. I also personally favored the 3 dimensional Wizardry 8 much more compared to the older titles of the series. But that's just my opinion.
If it's really true, that you could have finished the game anytime (by yourself), give it a shot and apply for a Steam-Release.