Yes, it should fit just fine.
No, the Magpul Industries Yugo Zhukov-S Folding Stock is only compatible with Yugo pattern receivers. Unfortunately, the standard AK47/AK74 version of this stock only fits stamped receivers.
The Magpul Industries Yugo Zhukov-S Folding Stock most likely will not fit the WASR10 since that rifle takes AKM furniture. However, the model at the link below should work.
https://www.opticsplanet.com/magpul-industries-zhukov-s-folding-collapsible-stock-ak47-ak74.html
The Magpul Industries Yugo Zhukov-S Folding Stock should work with a PSA AK104 Rifle.
Yes, the Magpul Industries Yugo Zhukov-S Folding Stock will fit the Zastava M70 because the M70 uses a Yugo pattern receiver.
The Magpul Industries Yugo Zhukov-S Folding Stock will not fit the JTS AK12 T1.
The Magpul Industries Yugo Zhukov-S Folding Stock is a stock and not a pistol brace. So it cannot be added to an AK Pistol without the correct ATF forms filed and approved.
The Magpul Industries Yugo Zhukov-S Folding Stock should fit unless you have an underfolder on your M70.
The Magpul Industries Yugo Zhukov-S Folding Stock Will not fit standard AK / AKM pattern rifles or Yugo rifles with underfolding stocks.
No, this is for Yugo pattern AK's, the US KS-12 says its based off the Saiga 12 style of shotgun. I can confirm this wont fit but as for what will fit, Kalashnikov makes the Folding AK Hex Stock for KS-12 which will fit or you can try the non Yugo of the Magpul Zhukov; it fits on the Vepr-12 so it should work on the KS-12, but I can not guarantee that.