A (hopefully) robust Merkle Tree library, with JS and Ethereum smart contract counterparts, capable of proving tree size, single or multiple element indices, updating a single or several elements, appending a single or a several elements, and any combination or permutation of the above, at the same time.
Let me know if you're still alive.
I might be able to make the introductions that would allow you to take this off the ground.
Hmu if you're interested @deluca-mike