I have a metal model my son gave me. He worked for the gold mine in Round Valley Nevada I will dig it out tomorrow and measure it. I believe it will be close.
OK............. You know how it is. You get something stuck in your head and it can't wait? I went out a dug out the haul truck model my son gave me ! I thought it was metal. It's plastic ! Anywhoooooooooo...it measures 2 3/4" long X 1 3/8" wide X 1 1/2" high. Sometimes... "Close is close enough" 'Quarter is for reference' .
I found my solution to keeping those box car doors from rattling open - Bard's Tacky Wax - Anti Sliding and Toppling Adhesive Sticky Putty You can find this on Amazon as well as other sites. I just put a little bit on the end of a toothpick and dab the lower corner opening. I then close the door and it stays shut without glue or anything else that would permanently alter the model. You can't see it and it can be removed without issue. Brian
I actually did get around to checking which doors opened first. Most of my Micro trains cars painted silver , SP Overnights scheme, would open nearly fully after a distance of 300 feet. Next was the black painted cars about half open at 300 feet. Ultimately the colour didn't matter as much as how glossy the paint was. I was able to get them to open a bit quicker by routing the train through lots of yard tracks ...... I think it's the vibration from check rails and rail joints which actually gets bits moving if they are slippery enough.