I can only see one mark on the telescope case and that is AV2506. That is the rifle number of which that case and telescope originally belonged. Indicating to me that it is not original to your rifle. But so what........ That's how things are in the real world. The old painted over paper on the left hand inside of the lid are the remains of the old user instructions. I can't see any other marks.
Figure 17 - unknown
.015 = height of foresight blade + 1" so it is 1.015" above the centre line of the bore
45 = barrel date and various proof or examiners marks
32294, beaten into barrel by over zealous ham fisted Indian in-examiner.
Find a local engineering company locally and get the whole lot dunked into their phosphating tank or chemical blacking tank. IMPORTANT: There should/must be a spring washer between the front trigger guard sling swivel and the trigger guard. Make sure there is before you put it back together. In view of the unknown history of your rifle I'd read up on how to calculate the correct length of the collar for your rifle and fore-end. The collar is the little round tube sitting underneath the magazine catch in your photo