Hi Cat.
My father was a Sgt with 145RAC, and I've been researching his military history. Back in 2007, my brother and I visited the Coriano Ridge War Cemetery. While there, I took photos of all the gravestones of the men from the Royal Armoured Corps. I've checked them and your uncle's is among them. Your uncle was L/Cpl 7948545 R T Hall, He was killed on 18/9/44 aged 24 years. On 18/9/44, the regiment attacked San Martino and a number of men were killed. From what I've learned, my father was very fortunate to survive that day. Some of my fater's 'mates' are buried there (Ronnie Quin being one of them). Ronnie was killed the same day as your uncle, and I'm therefore pretty certain that my father would have known your uncle too.
I have a copy of the 145RAC War Diary - I got it via the Tank Museum at Bovington. I've had a quick look, but can't find any reference to your uncle.
I've only just come across this topic (some years late)and have joined up today simply to tell you what I know. I hope you see it and that it is of help. If I find anything more, I'll add it.