The card warehouse doors now have some suitable detailing. I've always planned to try and include all the ironwork required to make the doors look like they should slide even though most people won't notice it.
Most of the inspiration to be honest came from the photo of the O gauge layout "Wood Street" that has inspired this model. While copying a model isn't as good as copying the real thing, in this case it looks like the builder got things pretty accurate. I can fully understand how the rollers work and in fact the inclusion of the bottom runners is in line with doors I've seen. It's just not something that people normally bother with. However our railway club has sliding doors and there is a channel in the ground to stop them flapping back and forth.
All the metalwork is made from Slaters microstrip. I keep multi-size packs in stock and just pick something that looks about right. Clever people will plan ahead and have lots of different packs of different sizes. I'm not organised enough for that and too stingy to buy lots of packs.
Door handles are from staples re-bent to be around the right size. Holes had to be drilled in the card to accommodate them as despite my efforts I couldn't push them through the surface.