Thanks Howard. I thought it was him but was not sure. Maybe there were other officers called Sims.....a bit like Tippit.....you never know.
I haven't checked but I figured the most likely answer was that Ruby testified some time after Sims or the penny did not drop with the WC counsel after Ruby testified. To me it seems that Ruby was keen to gain access/info regarding Oswald on the Friday. I had not known he was at the midnight press conference although I know he had corrected Wade regarding the "Free Cuba" comment. I figure Ruby had his pistol on him at that time.
I'm not sure of the chronology of the testimony. I tend to think the call to Sims was probably known of before Sims' WC testimony, but you could be right.
There's no doubt Ruby was keen to gain access from the get-go. He succeeded.
Ruby was already in the hallways of police HQ when Oswald was being moved to and from his cell for interrogation. He was caught on tape in close vicinity to Oswald on one of those occasions.
And he did have his pistol on him.