The Buckeye Steel Castings Co. 90-ton six-wheel freight truck dates back to at least 1910. These friction bearing trucks were used on high-capacity gondolas and flatcars, wrecking cranes, locomotive tenders and other heavyweight freight cars. Roller bearing versions of these trucks are still in use today.
There are a number of different styles of solid journal Buckeye truck available in N scale. The first style (which I believe is designated T-44 or T-44A) is an older design with outside equalizers. It can be found on Atlas/Roco, Bachmann (old), Bachmann (new), and Minitrix/Roco depressed-center flatcars -
The second style can be found on Bachmann and Arnold-Rapido wrecking cranes -
The third style is from Micro-Trains (also used on depressed center flats) -
The latter two are newer designs (relative to the first one). However, it's difficult to pin them down to specific prototypes since the later Buckeyes were available in many different styles (and with most being custom designed for particular cars and uses).
As for the primitive trucks used on the old AHM/Roco wrecking crane (later imported by Model Power and Con-Cor), well, who knows what they're supposed to be? Buckeye? Other? Your guess is as good as mine. Whatever the case, I include them here simply for the sake of completeness -
Micro-Trains makes the only mass-manufactured roller bearing Buckeye trucks in N scale (specifically designed for their 68' DODX flats) -
