Reading all the nostalgia makes me think of my first toy gun. Well, pair of toy guns.
Dad didn't build them, but he built for a living so that's OK. They were just your average cheap tin six shooters, but man, I loved them hoglegs. I tore up my toys pretty regularly (hyperactive kid!), but them two pistols were my babies. I don't know where they are, but I would trade darn near any of my real guns for them now. I graduated to real guns pretty early. I want to say my first Red Ryder (which my Dad still has) came along when I was maybe five or six (by which time I had already been shooting .22's with my old man) and my first real gun, a single shot .410 (which is in my closet now) came along when I was 8, followed very quickly by a Ruger 10/22 purchased new in 1977 and given to me unfired in 1979. Still have that one, still shoot it regularly. In fact, it has been my main .22 rifle from then till now. I bought my own first .22 when I was nine or so and my first centerfire pistol the year after I got out of the USMC at 22 yo.
My other favorite toy, my marbles, I have. This, of course, is handy because I can always tell people that I haven't lost my marbles. Jokes aside, I want to be buried with those marbles. Lots and lots and lots of hours as a boy winning them and having fun.