Is the Timeshare Investigation Board legit?

My husband and I bought one week of timeshare 1999 and another week at the same resort a few years later at Bahia Blanca Gran Caneria. We continued with maintenance payments till his death in 2004 I continued for a while then misguidedly tried ‘Sell my timeshare’ in 2006. They are under investigation by police and I got my £6000 back via sect 75 with Nat West about 2017. I used Preteorian Legal to get out of the annual maintenance contract as they broke off their contract with Bahia Blanca via a Tenerife address who owned the site.
However the initial outlay of £12,000 I am still out of pocket. As I am now 67 years old this money would now be useful to me. I was informed last year the company we bought our first year with at Bahia Blanca sold the business on 2000 and we had no new contract with the new owners for maintenance but we paid it never the less

I would like to sell our RCI Membership we bought in Las Vegas some 5-6 years ago. My husband’s medical condition and mine lately, has prevented us from using our facility.

I would now like to sell it.