I've been watching this build and am amazed at the level of detail, bravo! As for the gear oil issue, I went through an extensive search to find an oil for my 52 M38Cdn. Chevron makes a 90W or 140W GL-1 oil which is safe for yellow metals. Todays GL-4 or 5 will deteriorate yellow metal over time time due to the sulfur content. I paid approx $100 Cdn for a 5 Gallon pail. Keep up the good work