Erick,
The Scott spindle was patented by William Scott in 1865. It is the mechanism that horizontally connects the top lever to the Purdey double underbolt. The combination of the Westley Richards top lever, the Scott spindle, and the Purdey underbolt is probably the most common means to open and lock a shotgun. But it was still relatively new when your Daly was made.
The 26" barrels would be very unusual for that time period - never say never, but it would be unusual. What does the gun weigh BTW? The brass screw is of course a replacement for the ivory or brass bead that was original.
While there are over 275 Prussian Dalys in the database, there are less than 20 or so hammer guns - not a lot to work with really. The serial numbers vary greatly depending on the actual maker.
I'd love to see photos of your other Daly and hear how it is marked. #1100 would be an unusual serial number for an early Daly equipped with a Jones underlever.
Ken