Blue marans roos in with colored egg layers cuckoo marans and blue marans hens. You can get BSLs olive eggers blue copper marans and black and splash marans. If you want to get as much as possibly out of one flock this is what I would do.
I had been leaning australorp roo but I didn’t know why. I figured it out if you get some barred hens you can breed sex links with him and get SOP australorps.
Same with my Red Sex Link roo but he was to aggressive ( we didn’t know the BSL was a roo until later ) so we re homed him and the rest of our roosters except the BSL
I thought you were talking about him being SOP breed for a second there. If he is a production red he would be white plus the only leg color he matches is RIR.