K-Line codes

Today, I received a K-Line Husky freight car, Reading K646-1931 that I had ordered. It is really a nice boxcar and for such a low price.
Anyway I was looking at the car in detail and read on the side: “blt 7-61”. With Lionel cars “blt 72” means built in 1972, that is easy and even I understand that. This car is too beautiful and too modern for september 1961, that is fore sure.
Does anybody know what that code stands for. Does it mean anything at all?

Thanks in advance!

More to restore, glad you like that Husky car… they’re being blown out at a lot of places. There’s not for me, but that’s okay.

The built date was just laziness on the part of K-Line. They probably copied the data off another one of their more scale sized cars, which was probably taken from one of the photo rolling stock guides, since K-Line had a collection of them. The Husky cars were made from exisiting tooling and made on the cheap. Even though the box car is a woodside model, they just duplicated the info from something else to save money… simple as that. The build date refers to the prototype built date in this case. But of course, woodside box cars were long out of construction by 1961.

Lots of manufacturers keep the original built dates, even Williams, as to why brianel027 can probally explain that.
Lee F.