This project is awesome to hear/read about.

If they really can repurpose old gear and give it new life that would be awesome.

Not sure what the final design will be or how it will be sold but something to think about would be how to sell the units. I know in the automotive world they do "core" charges which means you are charged extra for the part until you bring your old part back in so that it can then be sent off to be reused/refurbished. Perhaps something like that could be done here. charge the customer an extra $xx.xx on top of the miner to cover buying new shells/fans incase they don't return the "core". This would allow those that have these older units laying around but may not have the skill/ability to take apart/rebuild a miner an option to purchase a plug and play miner. The other option would be to just sell the blades for each model and let the owner do the retro fit.

Cant wait to see what comes of this venture.