Hi PAVarminter!
It was a very good idea to post some pics of your Swedishicon Mauser. Looking at the pics I have some info on the holes in the back of the receiver. The holes in the back of your Swedish Mauser were drilled to mount a diopter sight. I have a Swedish Mauser with the same drillings; I am pretty certain that the diopter which was once mounted was a so-called 'Söderin'. The Swedish had many different diopters mounted on the m/96 rifles. They were used for longe range target shooting within the military and the home guards. If you are interested in this topic, there are some good books on Swedish Mauser diopters and accessories. Once a while you get some reasonbable Söderin diopters at ebay. Nevertheless, I recommend that you get a Swedish Mauser front sight hood for your rifle. I have one too and it is very nice especially for target shooting. If you have further questions, feel free to drop me a message.

Greetings from the other side of the big moist

Tom :-)