I suggest that you use the Enquiry Form on the TCA website I gave you above and ask them about it. I don't think you have anything to lose by doing this.
If you can still extract yourself the deal I suggest you do so - but I imagine the cooling-off period is long since past?
I believe that you will still have a contract with the timeshare company, and a separate contract for the finance. So just because your finance company has gone bust doesn't mean that's the end of the deal. You are debtor of the finance company and some organisation will buyout the debt and want you to restart the payments.
It shouldn't impact the Timeshare Ownership certificate.
But do your realise that resale value of your 'asset' is less than �2000? This is just one reseller's offering on one scheme - Canaltime at Alvecote - but they all similar.
Sorry to be telling you this but people are desparate to get rid of these things.
http://www.aberfoyleholidays.com/alvecote.htm