Old parts available in editor?

[Pds314]

Running a copy of 1.11, I have found that a variety of outdated parts are available in the editor if you go into advanced sorting and don't sort by function. Highlights include an older version of the Spark that's perfectly balanced as all thing should be (read: 30 kg lighter and 5 seconds better sealevel ISP than current Spark), as well as an old Twitch that's basically the opposite, incredibly underwhelming performance-wise.

All of the old parts I found in my editor:

[UmbralRaptor]

There are a bunch of legacy parts kept around for several versions so that older craft and saves are compatible with newer versions of KSP. Note that the slightly different shapes of the RT-5 and RT-10 variants changes their drag (and therefore in-atmo performance) slightly, despite having otherwise identical characteristics.

[JedTech]

I believe most of these parts are located in the "GameData\Squad\zDeprecated\" folder. Someone please correct me if I am wrong, but I think it is safe to delete this folder if you are starting a new save and don't plan on using the older versions of the parts.