A great example of those coaches we used to see on a daily basis Seth. They still look good today, unlike some during the 1970's.
Leyland's 'Panther' model was one example of a veritable rash of rear-engined single-deckers that came on to the market in the mid-1960s. It shared many components with the ubiquitous mid-engined 'Leopard'.
The basic idea was to replace crew-operated double-deckers with one-man operated 'standee'-type single-deckers.
Mounting the engine horizontally, (and gearboxes, in some cases) under the floor on the rear overhang brought forth previously unheard-of problems. Probably the most serious was when a body was 'tied' to the chassis aft of mid-wheelbase - serious stress-related failures often occurred within the body frame.
Alas, many led comparatively short lives, and Leyland operators generally returned to the trusty Leopard to satisfy their single-deck requirements.
One good thing about a Panther:
Like hen's teeth, and worth a pretty penny these days!