Cool bike! I like the orange too, its bright and looks great!
So I guess I wil lchime in on the breatehr thing since I have been thrust into a huge amount of research on the subject.
I have a 71 motor and the timed breather was on there as well. I had an issue with crankcase pressure and decided to look at all the componants over the course of time. The first thing I did was blindly buy a xs650 valve and attach it to my timed breather. I didnt get a change at al lin performance with respect to the crank case pressure. Not saying the valve is not useful but saying with it in the line with the timed breatehr it just does nothing.
I think the timed breather is only shooting air out so the issue with that isnt reverse pressure but the volume of pressure. The valve on top of the timed breather only adds a light restriction to the already restricted volume coming out. I think if all the pieces are working in order with the timed breather than thats good enough. If not then more volume would be needed? And that may drive the need to get a higher performing pcv unit. But that would need to be plumbed into the crank a different way since the timed breather is small.
So with my setup I ended up buying Jim's sump breather. I dont know if everyone would need that but I can attest to it being much more effective than the stock timed breather.
I also can say that I was encouraged by more than a few people to remove the xs valve when it is in line with the timed breather.
Cheers