Back when it was still pretty much the original bi-pin Pop-Pack, save for the new lampholder. These only lasted a few years, before they updated the design further to include plastic twist buckles to secure the cover plate, a simpler starter holder that sinply used a circular hole in the side of the spine and a slimmer ballast. You can retrofit the original style lampholders to these quite easily should you wish to too...

That looks brand new! I guess they brought out the oval ends when T8 came about to better suit the slimmer tubes but also still look acceptable with T12's.

That looks amazing and this is the next fluorescent fixture I am after for my collection - the oval shaped holder version Poppack

Nice save still looks in mint condition. Not many of this version about, only had a ~3 year run before the turnbuckle

I have one of these, about what years were they made?

The very start of the 1980's

Thanks for the info Slyspark.