If you can get a hold of a pressure bleeder set up you could send
pressurized oil through the hole were the oil pressure switch is located.
This would send fresh oil to all the oil races in the head and lowwer end.
Should also help flush out any crude from the oil channels.  Make sure that
the bleeder is clean before putting oil in it, because they are usually
used for brake fluid or hydraulic fluid.

I've seen little primer pumps set up to prepressurized the oil system in
diesel before they are cranked over.  Saves on wear and tear because the
bearings are definitely coated in oil.

Hope it helps,
Dave K.