shaft to chain conversion

[shredderhd]

Anyone out there know if the oil seal on the drive shaft will fit the middle gear shaft? I am looking into having a new case machined for the middle gear area and then attaching a sprocket to the shaft, etc, etc. What I am thinking of doing, doesn't look too difficult so far. Also, if the oil seal is interchangeable, how the heck do you get it off?

Thanks,
Terry Brady
82 XJ1100J chopper to be.