The chrome Ludwig drum set on stage at the party is from the 1970's. The chrome hardware that holds the cymbals/hi-hat are Ludwig Hercules models and were manufactured between 1978-1984. Both the K cymbal and the stand holding it are post 1980.
While Roger is singing to Jane at their party, the drummer of the backup band can be seen in the background playing a K Custom crash cymbal, though the K Custom line of cymbal wouldn't be introduced until 1981.