I removed both balance shafts from a DR500 without a problem but I have no idea what the crank is like in an SC500.
Personally Dave, I'd be leaving it in for now, the old girl will have enough go for an bloke making his comeback after 30 years on the couch.
It'll give you room for improvement later when the body gets back up to speed.
I can't believe I'm trying to be sensible.