Engineering Dr,
I realise I'm probably seen as "pissing on your chips" here, but the value of these forums is to allow different opinions to the OP and then let them decide.
From what you've provided, I can't see anyone making the leap from a person who has spent 90% of the last 20+years in teaching / research to someone who can command big dollars and "...offer solutions to sophisticated and complex unconventional problems". Sorry, but the chances of this working are, to me, very low.
So what would I do in your shoes?
A) accept the status quo if that is possible (your position is secure? and start planning for post work scenarios
B) Think about what anyone else in the organisation has done to "escape" the current role and move into commercial issues
C) Teaching establishments often generate spin off companies / associated science parks / collaborations with companies etc - can you get involved in any of them?
D) You will have more contacts than you think - they become your best entry into any other work. Think back to everyone you've known for the last 20 years and let them know you're looking for "new opportunities". Are you on Linked In?
E) Be realistic and flexible. I don't know what or how you established yourself to the head hunters but something clearly went astray - either you believe you are truly amazing and unique ( don't we all...) and set your ambitions far too high or placed restrictions on what you wanted to accept ($, hours, type of work etc)
F) Accept that you are what you've done and look to establish that as a separate business doing training / etc.
I can't offer or really see a golden path here based on what you've told us.
But don't buy or buy into a business, please.
A few years ago I got the chance to be part of a start-up consultancy and at circa 50 thought great - 10 years of this then they sell the business and I'm in. Got to the point of investing real cash as well. Three years later got out by the skin of my teeth with my investment paid back, but others weren't so lucky and not only were made redundant, but lost all their investment. Starting businesses is hard without great contacts and opportunities and lots of experience in that field.
You might like to check out the post below yours.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.