A self-powered dumping garden cart

Step 1: Brainstorming

I could really use a power assisted garden cart and it would put a cherry on top of it dumped. I picked up a free broken treadmill today and decided it was a good start. I will attempt to grow this instructable as the project develops but I wanted to put up what I have so that I can crowd source some ideas and maybe give some insight into the problem solving in order to help others adapt this project to their own needs.
First Ideas:
Use treadmill incline worm drive for the dump feature.

Use main treadmill motor for propulsion

Use treadmill platform for most of the frame/dump

Use rollers as axles

I have an old garden cart to cannibalize wheels off of

maybe try to rescue the speed controller, if not use an old cordless drill trigger.

Steering is a combination of bike parts and old pull cart rack and pinion system.

Old car batteries for power

Step 2: Opening the Treadmill

This treadmill was in a climbing Gym and obviously was exposed to some chalk. I have no idea how much this compromises the more sensitive electronics. it may not and just broke because the chalk caused heat build up. I will run some tests with my multimeter and see if I can find an obvious failure. Of you have any hints or tricks, please share.

Step 3: The Motors

I was not aware that dc motors came in 130v, but I found some forums that said it will run on less again I will test with what I have and report back. this is my biggest issue, how to power and control this beast. Ideas here are more than welcome.
Also the incline motor turned out to be AC current so I would need some sort of transformer I think to make the dump feature powered.