Your father has a 135K credit account. Credits are Worldmark's name for points.
Selling would require paying off the loan and you might get $10-15K for that size account so not worth paying $70K.
There is no deed for WM.
Renting credits means you keep the account but can transfer credits from your account to another owner. There's a form to fill out and it usually only takes a few days, but Wyndham, the management company for Worldmark, just 'updated' their website and totally screwed things up so it may take a little longer.
Go to this section in the Classified ad at wmowners.com; this is a website by and for Worldmark owners and is where you will get the best info and advise on what to do. You can look through this section to see what things rent for.
Classified for rent
Also look at the section on Memberships for rent to see what things are selling for. The rent and sale part at the top of the Classifieds is for discussions and is the best spot to ask for help.
When do those credits expire? ie. when do the new credits come in. When you rent, that expiration date makes a difference on how much they are worth. You have 2 years worth of credits that can be rented out. If your anniversary month has already passed this year, you have 135K credits that expire in 2025 and another group that expires in 2024. If that anniversary month is in the future, those credits will expire in 2024 and 2023. That last bunch will be of concern. You would want to get those rented out asap and then rent out the new credits when they arrive in his account.
Once you have rented out all those credits, stop paying the maintenance fees. You can't transfer credits if the maintenance fees are in arrears, so get those rented out first.
Sounds like he bought from the developer vs resale which likely means he also is paying Travelshare dues. The maintenance fees (dues) for his size account is $11209.42/year. Anything over that is the Travelshare portion. You can cancel that portion now. Travelshare is a developer add on that they use to try to entice people (like your father) to buy from them vs resale. The benefits are overblown and mostly worthless. Your father has a large enough account that he didn't pay any housekeeping fees, but since he never used it, there's no point. It doesn't transfer and there is no sense paying it while you get the credits rented out. If you are able to rent out all the credits now, ignore this paragraph and default on all the dues + loan after the credits transfer.