XJ600 N 1995 Engine & Frame Numbers

[KGR33N]

Hello, can anyone tell me if the engine and frame numbers on a 1995 XJ 600N should be the same. I have two RD250s and Yamaha did used to have matching numbers but the numbers on my XJ dont match which is puzzling. I know the provenance of the bike going back many years and it has only done just short of 13,000 miles ( backed up by MoT reports) and the previous two owners who I know well and trust did not put a different engine in. Anyhow it would be much appreciated if anyone could let me know if their numbers match. Thanks Kerry.