Practical advice is where I believe where you need to be.
If anyone is going to help we (the forum members that can help) need an assessment of the cars condition. BIGRich (Richard) can I am sure arrange that for you and let us know. If you have not already PM'd him via the forum (Personal Messaged) Richard for contact details then I am sure BigRich will contact you with the details.
There is detail you also need to assemble if there is to be any progress long term.
First the car without an IVA test is practically valueless to all intents and purposes, others will disagree with this statement but the reality is that the SVA/IVA rule changes mean that a-an-other owner who is not the builder will need to jump through hoops to get it tested. The 5Exi is notoriously difficult to sell at anytime, unregistered its almost a give away.
Perhaps Terry and Mark can assist but the facts of the matter are that as a commercial company they will likely want to pay very little for it, no disrespect to Marlin but that is what I would expect from a commercial sale. I could be wrong, perhaps a call to Terry as suggested by BigRich would provide the detail of such a transaction.
The items that will ensure progress are the original Marlin invoice, this identifies the chassis and the associated components as new and helps the process on.
The second thing that is essential is build photos, without these VOSA will not even accept the application for a test. Whether this is you or a nominee or an new owner the evidence required is the same.
The third item of use will be the engine and gearbox origins, if it was a donor car the V5, if they were new the original invoices are what is needed.
Once the car is tested then it has some real value, expect approx 50% of the build value on the open market at this time.
This all assumes it is close to completion, if its close then there is good reason to get it complete, I know of one person that maybe prepared to take that work on at cost.
If its actually a long way from IVA test condition the project is going to be a huge loss overall.
I hope this factual detail helps you make a choice. If you just want it gone i.e. “just get rid as soon as possible at what ever cost
”, that is a whole different scenario.
I truly hope this helps.