When we purchased our Marlin it did not have outriggers. I installed Lee "Seniors" myself ( I think they are actually MX series). Grady was able to send me a sketch that I used to give me the approximate locations for the mounting plates, without it it would have been very difficult. I also searched this site and the rest of the internet for Marlins that were fitted with similar setups. As ocnslr suggested, make sure you use backing plates and large fender washers. We fabricated roughly 3/8 inch thick aluminum backing plates, roughly 3 inches by three inches, they worked well. If I recall all the hardware was 1/4" diameter ss bolts, fender washers and stop-nuts.
I would reach out to Grady and do a Google search for images of your boat for the location of the outrigger bases. Oh, and I agree with ocnslr, they can (and do) hurt when you walk into the mounting brackets.
