G'day Stormy,
I'd recommend CRC 5-56 or Inox as good aerosol penetrating lubricants. Currently I use Inox liquid in a trigger spray, or 5-56 in the aerosol can.
Yes, clockwise to undo, with LH threads.
As these are BSW [Whitworth] threads and hex sizes, there won't be a metric or SAE inch AF socket/spanner size that's an exact fit, unless the nuts are a 'non Brit standard' hex. It may be necessary to buy a 'metrinch' type, or find a six-point socket that will work.
Impact is the next technique to try, if possible. Either a rattle gun and socket, or ring spanner and hammer, if a suitable spanner is available.
These nuts were always pretty tight, and on a machine of this age, odds-on they'll be rust-bound as well.
