Richie and Maury meet with Corrado Galasso at the "Sons of Mt. Etna", obviously an Italian establishment. In the window there is a green, white orange flag which is an Irish flag. The Italian flag is green white and red.
American beer was not available in Coventry (UK) in the '70s. Drinking from a bottle was not done in 70s UK. Glass in such a venue would not be allowed.
The reel to reel tape deck in the meeting room has the pickup reel (the large silver reel) on the wrong side. It is seen too be on the left, when it should in fact be on the right.
When Bobby Cannavale plays guitar, you hear chord changes, but his fingers are not moving at all on the frets.
When Richie goes to see Buck at his house, Buck goes on a tirade where he mentions Lyme Disease coming from Connecticut. The disease wasn't associated with Lyme,CT until 1975.
The light switches in Richie's house didn't exist in the 70's.
Buck Rogers rant about Connecticut refers to Lyme disease. The episode takes place in 1972, Lyme disease was not discovered until 1975 and was named in 1977 as Lyme Arthritis.
The audio equipment shown in the offices of the record company is modern equipment. It bears no resemblance to the equipment that was being manufactured in the 1970's.