1965 Valiant

welcome & thanks for your service.

first start by cleaning everything up.
to unlock the motor -- could be as simple as removing the spark plugs & pouring some diesel /tranny fluid in each cylinder letting it set up.
there are threads on here with different recipes for this type of stuff.

the main thing go slow & easy that engine has not spun in years-- rock it back forth slowly.

another thing is making a oil pump primer & spinning that with a drill to get some oil flowing over the metal.

start searching threads for specific problems & post up some pics-- cool story on the family car!

Lawrence