Quinncannon, Welcome to the Fire. It's a great place!
803504 is a 1965 manufacture date and sold as a Model 70 Target that was only available in 30-06. As for the G prefix...

I have seen several M70 that were made way before the G prefix was added to all of the production M70s. Those include G744,789, (375 H&H), G790,229 (Deluxe 30-06), G830,851 (264), and G844,295 (06 target). I have pictures of all of them.

I have no idea why some of these earlier (pre 68 GCA/G prefix) M70s have the G prefix. My hypothesis is that they were returned for work soon after the prefix was mandated and re stamped when they left again. OR, they sat around and didn't leave until after the prefix was mandated. Was there some confusion at Winchester regarding the 1968 GCAs impact on returned items? I have asked about this on other forums and no one seems to know. One thing is for certain, they are not common. Why do i know this...I collect 1965 M70s...yeah, im that guy.

Chip

P.S.
Im unable to PM you. I would love to have a picture of your sn for my records if you wouldn't mind.

Last edited by Centennial; 04/09/21.