I know what you mean about picking up the deer in low light conditions. My little Marlin 1894 sports a Williams FP sight and a more substantial front blade. I removed the hood and that does work better in the waning light. I have tried dots on various guns and the do well too. I do find they need a good "both eyes open" technique though. I've been playing with a new reflex type (Osprey, C-more and others) and it may be just the ticket for your little Marlin. Small, light and bright compared to the $30 red dots.