Re: K4 Decals
True, K4 has both their own website and an eBay store. I purchased two sets directly through their website since I'd rather support them that way-- fewer "deductions" if you know what I mean. There is a discount on multiple decal purchases and free shipping when using their site.
I have used some of their alphabet decals recently, and I'm pleased with the result though it's not challenging-- white decals on a black wall. It's also not on a freight car so I'm stretching a bit...