Thanks again, everyone! Did some more work last night, including waxing the screen (used Minwax paste wax). Amazing difference. It's a toss-up though - creates a hot spot on the screen, but more definition and brighter overall.

Logan, thank you. These were all hand-held, and honestly, a little softer than I was expecting. The shutter release button was sticky and stiff, and I think that induced some motion blur. I've since disassembled that and cleaned/lubed it, which made a lot of difference. I have gotten fantastic results from these old Tessars on several Automats, including pre-war models with uncoated lenses. I love them!