Carl, I think you may have hit on something I could accept as a reason for the odor comments.
Most of the "low pressure" or splash engines of the time, other than Chevy/GM were flat head engines. The road tube/filler cap was the only venting. No top of the engine valve cover vents.
The sludge build up in these engines were considerable as well.
Don't know how you guys handle oil changes, my recommendations to clients with restorations on these types of engines is:
High detergent oil
Change 3,500 mi or twice a year if low use or 5,000 mi or twice a year moderate use.
Have the engine at Full heat and start to drain as fast as possible after engine is shut off. Wear rubber gloves to avoid burns.
Using that method I have pulled pans after several years and found them virtually free of sludge in the pan and lifter galleys.
