Oil viscosity (weight) for model A

[redmodelt]

Oil does not evaporate in a months time and surface tension should keep some of it in the bearings. Even if the oil did drain out of the valve chamber there should still be oil in the bearings and dipper trays. Guess you could do an experiment, take two pieces of plexiglass say about 2 by 3 inches, spread some oil on one and press together with .015 clearance between the two. In a months time look and see how much oil still remains between them.