We've seen the premil receivers that were made into 1960 99E's with both steel and plastic buttplates. The catalog pictures definitely show plastic, but my guess is that since 99 plastic buttplates were new that they didn't have enough and just fitted steel to some.

So uncatalogued... but not unknown. I'll update my book on the next release about the buttplates, when I published we weren't sure about how correct the steel buttplates were on the guns we'd seen.

There were 3 of the Style 2 99E's at Tulsa, all in 300 Savage. Even though all very rare, nobody was really looking at them because they don't look like much. I dang near replaced the one I had, they were all nicer than mine. I'm guessing you ran into one of the same rifles. I do not recall if which ones had steel or plastic buttplates.. maybe Rick took better note of it.

“The Savage 99 Pocket Reference”.
All models and variations of 1895’s, 1899’s and 99’s covered.
Also dates, checkering, engraving.. Find at www.savagelevers.com