I have been scammed to of few cents and I missed completely this request. Not a big deal... The guy Liam Alexander Short, seems to be the liquidator,
https://www.thegazette.co.uk/notice/4510144 This has been discussed also here on bitcointalk (I found some references).
The offer however seems to good to be true. Why you should refuse so much money? Why not just trying to get a line of credit maybe giving this as a kind of collateral and not just selling? I know that is hard selling and used as collateral... just wait its not more easy and profitable?
I thought they calculate BTC debt but the Estate has sold the assets already. So it's pro-rata on the sold assets, it was valuated at. 12 btc = $150k. Ouch ouch but well.
It was naive to believe I can sell on bitcointalk because you need to be a professional. I am more informed now.