....and the results are in; ring has been removed. It might not be pretty, but I was able to break it free this evening with channel-lock pliers. 
Before attempting, I unscrewed the junction box assembly from the tray and worked the audio wires a bit so that I could pull the tube out. Then I held the box down firmly on a sheet of rubber gasket material on the edge of the workbench with the rest of the tray laying down next to it; (there was just enough slack in the audio wires running through the tube). It wasn't easy at first, felt like it was held in place with a gummy material but couldn't actually see anything. The more I unscrewed it, the easier it got. 
The ring has a fre "extra" grooves in it, but lives to see another day if I should need it again. Perhaps the Evap-O-Rust loosened up the corrosion just enough.

Matt
W2NS

On Tue, Aug 19, 2025, 10:18 Matt P <mgpaulonis@gmail.com> wrote:
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)



On Mon, Aug 18, 2025 at 8:24 PM Matt P <mgpaulonis@gmail.com> wrote:
OK Gents,
I am absolutely stumped: what is the secret to removing the retainer rings on a plug on a FT-233-A single receiver rack? I am finally getting around to replacing J-24 and have soaked it with acetone to disolve the laquer that was applied to keep tge retainer ring in place, but still no joy in getting to even budge. Do I just need more acetone?
73
Matt
W2NS