LowNSlow,
I think that with an FI of only 103 this is one of the 'younger' (in fatigue life terms) Bulldogs around. The purchase decision depends on your anticipated usage profile, so here's an example: I fly about 80 hours per year in mine, which has an FI of nearly 107, and do aeros about a dozen sorties per year - usually 3 to 5 looping type manoeuvres which click the +3.5g FI meter and a load of rolls which occasionally notch a click on the -1.25g FI meter. I also do the occasional spin just to remind myself not to do it by accident. At this rate the FI will reach the critical 114 in about 20 years or so. I'm pretty happy with this, and anticipate that in time there will be a collaborative effort among Bulldog owners to address the spar mod en-masse with potential cost benefits for all. In any case if £20k buys me a new lease of life on the aircraft it's cheaper than buying another aircraft with anything like the Bulldog's capabilities.
Regarding engine life, the TBO is 1,800 hrs, but check to see if it has had an top overhaul in the meantime - quite a lot of RAF Bulldogs got an unneeded top overhaul due to some issue with a maintenance company, and of course you can run on extension anyway. Mine is at 1,900 hrs and still fine. There are a couple of excellent Bulldog-expert maintenance outfits around, so I'd advise using one of them.
The Bulldog's beauty, in my eyes, is that it makes an excellent tourer with plenty of space in the back for luggage, bikes, etc, but with the ability to throw it around like a mini fighter when it takes one's fancy. It's a great handling aircraft, even compared with the Chipmunk. (I have one of those, too!).
ACL
www.airborneclassics.com