I am sorry to see them close as well.
I bought my first brass model from them, a C&S PFM 2-8-0 in HOn3. I still have it.
I started doing business with Caboose in 1964 with my lawn mowing money and money made doing other jobs. They were at 510 16th St at that time in one storefront. When they expanded to the store next door, WOW! It was huge for back then.
Glen and Bert were the mainstays back then with a rotating cast of employees going through there.
I bought my first LaBelle kit there as well... I wonder what happened to them??
I was always able to talk to Duane and Joanna after Glen and Bert retired as well. It is nice that the Millers can retire, but the circumstances just suck for us modelers and the City of Denver. Another victim of Gentrification. I look for the whole block to go down and be rebuilt "Bigger and Better". Yes, you can go online, but it is nothing like being able to go down to the corner of Broadway and Virginia and go out to lunch with the guys.
Good Luck to the Millers and to all of us modelers.
Rick