I was looking at a freight car kit by Branchline Trains, any guess on the age of this kit?

[tc1961N]

It's a Robin Hood beer freight car. I was wondering if this is 60s 70s, 80s or what.
HO Accurail Branchline 13716 Robin Hood Beer 40’ Reefer Kit FBX 5301- How old might this kit be?

Thanks

 

[bnsf971]

Wood sided beer cars were used into the 1950s, the 40’ version was around from the mid-1920s onward.