Also has a lightened trigger housing, and the scope mount bosses have been machined off.
Duffys was also the seller that had 2 "guerrilla gun" barrels on GB several years ago. One was a complete barrel assembly, the other was missing some parts. The complete assembly was discussed here and folks thought is was a "bubba" barrel due to rough welds.
Having researched these guerrilla guns, chatting with Different and member Leid (who saw several when out of the country), studying the pics of X-41 on the SA national museum site, it's interesting to note that there was no "set" standard as to how these GG were made.
For instance, the barrel assembly mentioned above, at the chamber end, was turned down slightly to help shave weight off. H&R tried many things to drop the weight. I don't remember off hand, but IIRC it's mentioned in the B. Stevens book that H&R was able to shave off as much as 2 pounds.
I always found it odd that the folding stock rifle on auction appears to have a full length/size barrel. I can't tell for sure if the chamber end has been turned down or not.