#zelda hack

I started this hack a couple of years ago but it was soon abandoned since I got stuck creating the pretty complex overworld.

I thought I might give it a try again! The overworld is about 70% done. My crazy idea is to base the whole overworld on the worlds of Super Mario Bros 3.

There are things I wish to add to this hack but I'm uncertain how.

✅ Mario themed graphics ✅Change text ❓New music ❓Bomerang grabs items ❓Select weapon with select 😴 New dungeons (I know how but unsure if I want to) ✅New overworld (70 % done)  ❓Automap that represents new overworld ❓Speedup all text ❓Make player move faster ❓Master sword always shoot ❓Make flute take you to certain spot ❓More than 255 coins ❓better hitboxes for items so you can pick em up easier ❓Better use for magic book? (Perhaps tanooki powers to make Mario turn into stone for a while?)  

I know there are already patches for a lot of these things (like the automap). But the thing is that I used The Legend of Zelda prg1.nes to make the levels and none of the patches seems to be  compatible with this version. Do I have to start from the beginning or can I move my overworld and grapghics to a dissasembly project or a prg0 rom?