Very nice rifle. Good scope set up. I am still looking for a good claw ring mount to go with my claw bases for one of my 1888s sporters. I have two that are so similar to yours. Mine are full tapered octagon and not octagon to round. I have two with shrouded barrel as sporters. One carbine and one rifle. The set up of the mannlicher clip permanetly installed in the magazine well for scope use is a transition piece. It is difficult to seat cartridges, but works well afterword. My rigle intended for a scope has the external inline magazine removed and an internal 3 rd magazine built in. It is slick as snot. (excuse the reference).Please listen to Peconga. Most of these remain chambered for the J=bore .318 bullet. You can find good bullets from Woodleigh in 200 gr and 180 t0 220 from Hawk. I find the Hawk bullet in the thinner jacket too week even for a 2100 fps 220 gr. load. Us the .035 jacket and they will hold together better on game. They shoot to the iron sights well.
\Your rifle, if this is an original scope and mount set up, even with the replacement but pad could value to $1500 to $2000 in best condition. This could be good for insurance value. You can still find a nice one from $900 to $2000 and in various calibers. I have seen some rediculous values in the $3000 range, but they don't sell near that. Yours is a name Haene. It brings the better price and value. Most are un-marked. My carbine is a Schilling. The two that are similar to yours are unmarked as to maker.
Load this rifle accordingly with intended loads (200-220 gr at 2100-2200 fls) and pressures 40,000 or under PSI and you will have a very nice and proud rifle of great heritage. I have hunted and taken boar and deer with mine. I will be taking moose and blackbear most likely, here in Alaska. they tend to be my favorite "go to" rifles.
Congrats.