That's a neat book - had a copy about 7 years ago when I was wondering how the other half lived and was looking for fresh ideas for the next (now current) motorcycle project. It introduced me to cut & fold honeycomb construction, which intrigued me enough to get a surface treated Nordam drop off of eBay for dirt cheap to...fondle and stare at. Had to study a lot about bonding aluminum. Not sure I'll ever use that construction technique, but it is good to know.
It also introduced me to the concept of flexural pivots for suspensions - not a lot out there on that subject. Loads of cool example pictures, but what I really wanted to know a lot more about was the differential - other than a basic "Yes it needs one and it can be done", there was no helpful information. Sold it soon afterwards. Might have to get another copy and see what I missed...
Lots of reasons to run a bike engine - I have decades of experience with them (In bikes, oddly enough) - I'd rather run a car engine in a car for convenience/laziness reasons.
I've tried all of the Terrapin plans source leads that I could find (And that "MiataV8' " posted - thanks!), but no responses, yet. The "Jawfish" Terrapin forum seems moribund - no response to a membership request sent several weeks ago. No responses from Rob Macknay from any of the email leads yet. Might just need patience - this isn't killing me....
At least one Mk5 is still active:
https://www.youtube.com/watch?v=ibVkPkZ5ENU