Mosley was a beast at 135. Floyd wasn't at his best at that weight. I'd give the edge to Mosley due to those facts.
Mosley had the benefit of not fighting anyone good at 135. He has a lone deserved win over an extra talented boxer (Oscar), likely due to Oscar's robotic gameplan, and otherwise proved time and again that a jab in his face and some defense/lateral movement were enough to offset him.
I think a better question would be if Mosley could beat Marquez at 135. Marquez would be at a big athletic disadvantage but had the discipline and skill to make it a tough fight.
...as if Mayweather doesnt use PEDs... like he hasnt been caught taking illegal hand injections (this is why he fights exclusively in the last state to allow it), and masking agents. Its funny how he and his fans loved pointing the finger at everyone starting with Pac but if you track their fighting weights by age they grew up in divisions and success at a very similar rate. But yeah, lets pretend Mosely used banned peds way back at 135 and Mayweather never has. Lol. Take away away Shanes roids and the hand injections of Mayweather and I make it an even easier fight for Shane because I dont believe he was using in 1998 and Mayweather admitted he was at 135 on live tv because he was too stupid to know he was breaking the rules. P.s. hows your video coming? Mines almost done. P.p.s. hows your artificial intelligence fantasy boxing match computer coming along? You know, the one that can recreate a complete film of an entirely accurate fight from 1900 based on nothing more than a single photo? P.p.p.s Colorize any more fights to help you actually understand what you are watching?
Put him against the Floyd that took Corrales to school and he losing a 10-2 type of decision. No doubt that type of Mayweather would show up for a fight of this magnitude.
Floyd wins this comfortably. Just keep popping Shane with that jab and he'll lose interest quick, Floyd might get rocked once or twice though, maybe lose 1 or 2 rounds but overall he's way too good for SSM.
He did not lose quick interest from DH's jab. To be honest, you do not seem top realize that Mosley was not 38 at 135 pounds.