Thanks, coastergirl. Walter must be very floofy! He doesn't sound nearly as big as he looks 
I'd guesstimate FattyCat to be 3'6" top of noise to top of tail when lying on his side. I had to measure different bits at different times and add them up, hence guesstimate. Compared to yours, YesItsMeIDontCare, 6.3kg sounds like maybe just a little more than he should be.