Well, why don't we add some of that info here.

Cox has apparently eliminated most of its line. It still has the Tee Dee line and the Sure Starts. The sure Start is the same as a "product" engine.

Some of the product engines with cylinder turned to the side or inverted do not include the prop screw and washer.

They appear to now make a generic tanked reedie called the Babe Bee. This combined the Black Widow, Texaco, and Babe Bee into one offering. It appears to use the plastic backplate, plastic tank, and Sure Start front end. The end result appears to yield an engine with Sure Start handling, plus a tank. This is all speculation on my part. Perhaps they intend to make the others again.

There are differences that may now be lost:
The Texaco had a smaller intake for increased intake velocity to yield better fuel draw with a large prop. It also had extra head fins on a special glow plug to better disapate heat.
The Black Widow had a "Stunt" tank to allow flying inverted without spilling fuel out the tank vents.
The Babe Bee had a single intake bypass to provide easy starting and handling.
The Tee Dee might not have the older high compression glow head with the "squish band" these days. (I do not have a current production one).

The Gloden Bee (from pre-Black Widow time) was sort of a cross between the Babe Bee and the Black Widow in that it had a single bypass and a stunt tank.

There were other things like hard anodizing on the crank shaft bearings and tapered cylinders on some models but you can't tell those from looking at the engines.

Hope this helps someone.

George