This site has a lot of info on the Sheridan including many photos and diagrams:
http://www.eaglehorse.org/4_ftx_gunnery/equipment/m551_sheridan/sheridan_intro.htm
It basically covers the history of the tank from the design/concept stage to its operational
use.
The Sheridan is certainly a subject long-overdue for a decent 1/35 kit! (Apart from having no interior
and being originally designed as a motorized model, the Tamiya one has been OOP for ages and very hard
to find, particularly at a reasonable price). Let's hope the Academy one turns out well.
Has anyone here built the Airfix 1/72 kit of the M551? - what's it like accuracy/detail-wise?
Some of the earlier Airfix armour kits (e.g Tiger, Panther, IS-3) are awful, but their later efforts (such as the
M3A1 halftrack, and Bofors gun with Morris tractor) are very nice.