There's only 1 small problem bro...that's not your crankcase breather ;) Those are reed valves and are for you air pump. Your crankcase breather is on the lower front side of the airbox that goes directly into your engine. There is actually no need for you mod at all, instead of cutting the pipe just vent the reed valves to each other and you're done. Check this out:
You can see what I did to block my reed valves to prevent backfiring on decel running my BMC/PCIII/Slipons.
P.S. Great effort though...and really nice pictures.