That is pretty interesting Rick. I am curious if there was something lost over time relative to that story. I base most of the following on Gaddis' book, conversations with Gaddis, and collaborations with other collectors like Bob Hunt, who devoted a substantial amount of time researching Springfield Randall's.
The most likley scenario we came up with is Larsen procured a standard type cap nut up in the industrial north and drilled the hole or had it drilled for the thong. I do not beleve Bo Randall made one much less all 1500 or so, particularly without the machine shop equipment to do so.
I will add, when would he have had time to make those for Larsen and why would he do it when Larsen could have used a atandard hex nut like Bo did? Remember, Gaddis stated tang nuts were difficult for Bo to obtain at certain times during the war. That is one more reason it is highly unlikely Bo would be making or procuring a unique style of cap nut to send to Larsen when he was having some trouble getting standard hex nuts himself.
I have seen two Orlando made knives with the Larsen/Springfield style nut, a model 1 and a model 2, so there probably were only a handful made. With Gaddis' input and research done, the general consensus has been is that those nuts and maybe a few more were part of stuff (to include complete Springfields and some parts.material) we know Larsen sent Bo to show what he was using and/or to fullfill a request by Bo for some materials i.e. nuts and brass.