@Bruce Mattes, Here are 3 Examples i just pulled up on Gunbroker, ALL 3 are TC Seneca’s like i spoke of above. I checked my Seneca in my Safe, it has the Flush Plug with
NO Flat Head Slot. Another odd thing, I have
ONLY Seen these Opposite side “Slotted“ Cleanout Screws on the TC Seneca’s, I personally have never seen one on a TC Hawken, or Renegade? That’s not to say they Don’t exist, But i have never seen one on them, They have ALL been Flushed Off, and Blued Over
Here is one that Somebody Boogered up trying to remove, Probably a combination of being Froze up, and a POOR Fitting Driver/Driver Bit (Quite common to see on ALL “Clean Out” Screws)