I would go straight to the rebuild personally. To me with compression that low on one cylinder I think you would have more of a headache trying to get it to run than if you rebuilt it. Also with you having another one to ride it's in no rush so you can take your time rebuilding it
How I explain to people about clutching a sled, its about Give and take. You cant have a Drag racing set up that is good on the trails. For people that will Clutch your sled. I know we have a member that does kits, But his name is slipping me right now.