Pete.
As others have said don't make a snap decision on this until you know the outcome of retained vision in the effected eye.
Here's hoping for a fantastic result post surgery, but as it sound like you won't find out the post surgery vision until July / September, it will be getting on to be too late to sell the Mog anyway.
If it was me I would keep both cars until the result is known, then worst case scenario at least you are familiar with your current vehicles and better able to peddle them about.
In the meantime it is very enjoyable and no doubt therapeutic to look at the ads for various exotica and ponder!
Best wishes
