Thanks for your kind thoughts everyone, my dad is still hanging on, but his condition is deteriorating, so I'm not expecting that he'll be around for much longer.
Like Tim's dad, his weapon of choice was a Pentax, and he took it all around Europe and the US. "Slide Nights" were a big social event at our place when I was a kid, and I successfully avoided most of them, whenever possible.
Dad would have the old Kodak Carousel projector set up in the lounge room with a dozen or so cassettes ready to go, Mum would serve their victims, er, guests all manner of snacks and drinks while the room slowly filled with cigarette and pipe smoke. Luckily for me, the smoke was usually thick enough for me to Leopard Crawl out fairly early in the proceedings.
He did take some wonderful pics though, maybe we'll hold a Slide Night in his honour sometime soon. Cheers, Terry.