The portable TV/Stereo combo that Oz buys from one of the other site workers is a Sony FX-414, which was a real model, sold from 1979 to 1983 in various Japanese/US/European forms..
Oz and Dennis travel to Liege to support Sunderland FC in a friendly match against a local team. However, both are fans of Newcastle United who are big rivals of Sunderland. It seems hard to believe that they would travel to support such a big rival. Although it's likely just an excuse to go for a drink elsewhere.
Oz travels to Liege with Dennis to watch Sunderland. But in the first episode when Dennis asks him about the Sunderland sticker on the car, Oz says it belonged to the man he bought it off but he himself wasn't a fan.