Atomic Bomb Dolley/Trailer

Cant find much scale-worthy information, but I did come across some pics of the trolley - it looks like the same one was used for both bomb's. I would imagine that it could have been a conversion on some other piece of loading / logistical equipment (?), If it was, it's cranked hubs & low centre of gravity suggests it was used for something pretty heavy - an engine possibly. All speculation, but here are the pics;

I have just noticed that these pics are all numbered in a similar fashion, in the top right - suggests there is possibly an interesting full set out there somwhere?

Appreciate the help.

The numbering in the photos is an artifact from the originals taken in 1945.  I have seen the originals at the National Archives (College Park, MD) and have copies of several.  Unfortunately, many details of the trailer, especially of the front and rear, etc) are not clear and open to guesswork.  The historical record in the archives gives no clue as to the type trailer, manufacturer, or whether it was modified from another in wide use.  Perhaps someone might recognize it from other uses (Ordnance related) during WWII, e.g., aircraft engine repair, tank engine, et al.

Curt