I have an 1870 Remington RB in .43 Spanish Reformado. I am developing the load for this gun and have come to realize my 67 year old eyesight is not quite up to the open battle sight system on this gun. (Same problem with my 30/40 Krag). Does anyone have any suggestions on installing some other sights on this RB that doesn't entail drilling the receiver or tang. I can make a mount that will fit the stock ladder sight hole but would like some idea of what I can mount on the gun. I think from my reading that some type of Peep Sight will help me see better and if that is the case would like some ideas on installing one. Any ideas appreciated!