Yeah that's a tough one.
If it was me, I'd probably go ahead and do a redesign, and then show them before showing the world. This conversation can help you in a few ways:
1) they may provide additional context around why design decisions had been made, which would help you to understand the problem better
2) they may be very risk-averse, and not like the very idea that you would do this. Good to know when weighing up your decision of whether to publish it online or not (I'm an upstart, so I probably would go ahead and do so anyway, but that's me ...)
3) they may really like what you've done and offer to buy your work/expertise/input on developing it further
Hope that helps.