In Mother Natures Son, when the Trotter's check in to the hotel in Brighton, the porter is carrying Del Boy's leopard skin suitcase. This however, is the same suitcase that was stolen previously in Miami Twice Part 2.
In the first episode Del says he's 12 years Rodney's senior. Yet in series 4 (1985), it's 21 years as Rodney's 24 and says "it's Del's 46th birthday in a few weeks," suggesting Del was born in 1939. In the final episode, Sid's got a picture of Del taken in 1960 when he was 15, now he's born 1944-45.
The Reliant Regal from series 3 onward bears the licence plate DHV 938D, indicating a vehicle registered in London (HV) in the year 1966 (D). But the vans used in these series are later models from 1972 and 1973.
The Trotters' Reliant Regal van is depicted as corroded, but this model actually had a fibreglass body and could not rust! All the rust is painted on.
Uncle Albert keeps talking about his experiences during World War II, yet the Trotters know from the revelations at his trial that he was never stationed outside the UK.