I am really impressed with the prompt feedback and recommendations, thank you! I messaged Steve and said that I would be patient with this, as brute force hasn't made the slightest effect. In fact, since there were a few mentions of corrosion within the threads, I thought I would soak with Evapo-Rust for a few days to see if that may impact. I will keep you all informed when I take my next stab at it.
I have a few more observations from my SCR-274N restoration and will share these under a different Subject Line. This has been "on the bench" for quite some time, but after seeing Mark's (K3MSB) posts of his recent display, I am back at it again.
Matt
(W2NS)