Not sure if I have any 254 deflectors or not, but don't sweat it. It's not a big deal to have it on there anyway. Those plates weren't on most of the 200 series saws until halfway or so through the models runs. So, there's plenty of saws that never had them at all.
I can't say if the KS cylinder is better or not. Or with and without the deco is another one. Sometimes stuff just gets labeled better because it's less common.
Couple things on that 254 if you are still hunting parts. There were some differences on the starter side between the early saws and the later saws with the air injection. The left side of the crankcase was actually different, along with the air conductor. But the early "small decal" starter used a different pulley that the later "large decal" starter which is deeper. Either starter works on any saw, but you can't mix the internal parts.
I think 254's run better with .325, which is how I have mine set up. Not saying 3/8 is bad, (and don't want to ignite that debate here), but I like 'em with .325. But the small spline drum is NLA from Husky. Not sure if Oregon still has one or not. So, if a drum needs to be replaced then 3/8 might be the only option for a guy.
You guys KNOW we are going to have to have a 200 series fest at Walt's when the weather breaks, right?