remember the Bativa line were the "Economy" models. thet didn't have as fancy wood, checkering patterns & the engraving of the higher grades had nothing to do with the design of the locks. They also lacked the block safety & the draw bolt. The normal safety simply blocked the triggers from being pulled. The Block Safety was an extra safety which in the event the hammer should be jarred off without the trigger having been pulled prevented the hammer from striking the firing pin.
I am sorry that when you mentioned the bolt in the barrel lug, I failed to note it was spring loaded, & was thinking of the Draw Bolt. As others have pointed out this was a bolt which went crosswise through the barrel lug & fitted into recessses in the frame. This bolt was to help absorb the axial thrust upon firing & take part of the load from the hinge pin.
Many English & European guns having double underbolts have the front face of the rear lug cut on a radius centered on the hinge pin & rotate into a matching radius on a cross member of the frame for the same purpose.
Likewise I have never heard of a Batavia model baker having either the Block safety or the Draw Bolt. Understand that in this context Batavia has nothing to do with where it was built, but is the model line of guns referred to as Batavia's. Higher graded guns were built in Batavia which did have both the Block safety & the Draw Bolt.
