This is only for my situation, your's appears a bit more complicated. My choice for a close quarter scope for my Marlin Guide Gun (.45-70) was geared to the following:
1. Limited range of the caliber to make reliable hits.
2. The stubby weapon (18.5" bbl.) and overall 37" long.
3. My particular hunting situation (hogs at close quarters and fast moving out o 150 yard shots.
4. Economic by having limited funds.
My research landed me with a Leapers long eye relief 1.25-4 scope with red and green illuminated mil-dot system. It is short, light, and has stood up to the .45-70 without a hitch. The 1.25 mag. is almost looking thru a window with crosshairs, but going up to 2.5 it is super great at pulling in the hogs I shoot and still give me a wide field of vision. Plus, with a low power mag. there is little "wobble" in the scope and this creates faster shots as I'm not trying to get the crosshairs too "pinpointed". The scope at 4 power is just enough mag. to get good shots off at the extent of my range of solid hits (150 yds.) and still keep the "wobble" factor at bay. Plus the range finding aspect with the mil-dot is really good. At 4 power there is plenty mag. to see far beyone my usable range and I would not bat an eye to use this scope on a much flatter shooting weapon.
The cost of this scope was $58 delivered. Rings and base about $25. The smile on my face as I see a hog drop in it's track...Priceless!
Wade