On a private testnet, how to get UI working?

[wbl]

For reasons I want to do development on a private testnet and make sure my ERC20 contracts work with Uniswap

I ran this script, and deployed some ERC20 tokens, and started hacking on the interface to make it work with the testnet using the addresses from state.json. Unfortunately I was only partially successful. Some documentation, or better yet a way I can dump state.json into the frontend and have it magically pick everything up, would be a big help.