help me identify my parker gun

[Daniel Bjerkmo]

Hi I wonder if you guys can help me determine the model of this gun, the serial nr is 67154 and is made in 1891, its a 12 ga.
From the identification guide with the P under the serial number on the action , it should be a grade 1 gun, but with hammers, but this is definatly a hamerless gun so I am a bit confused, can you guys help me out?
I would say that the gun is in a great shape and is a fully working gun with no damages or corrosion, what would you say that this gun is worth, and the gun case in the picture is this the original parker case that came with the gun? at the barrel rib it says Twist at the end.

thx a lot guys!