The Athearn 50-foot flatcar has proved useful for kitbash projects too.
Way back when the Intermountain 70-ton flatcar was just a twinkle in their eye, I kitbashed a couple of 70-ton, 15 stake pocket flatcars by cutting up two Athearn 50-foot flatcar kits and splicing them back together (tossing the ends with the brake stands). The cuts were offset and not directly across from each other and I made a replacement deck out of Evergreen styrene sheet. Made for a reasonably credible model since nothing else was close. The Ann Arbor RR got several of these second-hand from the DT&I (900-949) which were all modified for specific service. The DT&I had rebuilt four of them with bulkhead ends for hauling pipe - on the AA they were used for "hardboard" (Masonite). Others got modified stake pockets and side racks installed for hauling telephone poles. These racks could be moved to different positions on the cars to accommodate different lengths of poles (they are not movable on the models as they wouldn't stand up to the handling).
I had copies of drawings of the stake pockets and side racks from the DT&I engineering dept. which I used to build a couple of models:
I have seen photos of NP and Soo Line cars which appear to have similar, if not identical, stake pockets and racks which leads me to surmise that these were a commercial product and not home-shop fabricated.
The Athearn kitbash also produced a 70-ton DT&I flatcar loaded with 10 Wiking tractors ("Ferguson" models which are very close to the Ford N tractors in a prototype photo). I call it my "$80 load on a $10 flatcar" since I picked up the two Athearn flatcars for $5 each at a swap meet. I have toyed with the idea of replacing this kitbashed flatcar with the nicer Intermountain model but haven't worked up the ambition to redo all the wheel chocks and tie-down cables.