Martin,
What kind of die-cast? I'd rather collect die-cast as well. I've got about a hundred Postage Stamp Airplanes from this company:
www.modelpower.com
All are still in the boxes and I've learned that many are no longer in production. Also, I have a few Matchbox Collectibles (1/72 scale?) of Spitfire, P-40 Warhawk, F6F Hellcat, P-51 Mustang, P-38 Lightning and F4U Corsair that came out a coupla years ago. Dragon's Warbird Series has a few nice ones as well. The only plastic model in my inventory is an F-105 Thunderchief that needs a good home.