John F.
1811's have automatically releasing check valves, just push it slowly to move it with the engine off, some resistance will be felt and is normal.....don't do this any more than necessary.
On your Original, yes they have some value, but no more or less than any other good running 30+ year old Cub Cadet, no "need" to retire it as a collectable if you don't want to, just use it and care for it like you would any quality tool. Good condition plain-jane running Originals are $300 tractors (+/- depending on options), while very early low number (Serial #'s XXX and lower) fetch more for true collector value.
Run it, enjoy it, and take good care of it.....IH Cubs are made to enjoy!!!!