The above does not tell me that you necessarily have water in the cylinders at all. 12+ SCR is a high compression engine. The battery may be down after 5 weeks setting. And the rough running may be due to the charging system having failed and the system voltage being low.
First I'd measure the battery voltage without ever touching the starter. A decently charged and good condition battery should be at 12.6 volts or thereabouts. If OK, then look for water. If battery is low, then charge for 1-2 days, and then try again. Once running, see what the battery voltage is at 1500 RPM.
I'd pull the plugs and look for signs of water and then crank it over with no plugs installed and look for water. If no signs there, then measure the battery vol