Hi Martin
Ah, I feel better now having read your note, which does tell me you have thought the process through. There is nothing worse than making a "knee-jerk" reaction then regret it in the fulness of time.
Although I can only view the car from small images on the Boardroom, it does look a tidy example, seems to tick your boxes and therefore worth you to view the car in the flesh. Regarding the agreed value figure, I never comment as I believe the agreed figure is between the buyer and the seller only and not the World and its mother. You will already have a price in mind via previous re-search so stick to it
Regarding the X-Flow engine, I did, a couple of months ago make comments in another post on a different subject but cannot find it at this moment in time. Basically, the X-Flow unit is getting a little old now but still is a cracking engine. Have a Google search to understand the X-Flow history and success that followed.
The main reason X-Flow's are reported to leak oil, water and experience mechnical failures is, in my opinion poor assembly of the relevant components. During my time I have rebuilt more X-Flow's than enough and have never had problems afterwards, just use plenty of care and attention to detail during the rebuild.
Finally, you do not need a modern engine producing a shed full of BHP to make a Westfield a fast car. What you do need is a car that has all components optimised, e.g. the engine set up on a rolling road by someone with the appropiate experience, Gear ratios that suit your purpose (both Gearbox and Final drive) and Suspension Geometry. These items optimised will certinally make a difference.
Good luck with the car hunt and let us all know your final dicision and most importantly, enjoy the experience.