No, the Pincer Placard will only work with Gen2 and 3 Placard Capable K19 plate carriers. You can make it work with your Gen 1 K19 Plate carrier with a placard conversion kit that you can order from here:
https://www.axladvanced.com/products/adaptive-vest-placard-avp-for-jpc-molle?_pos=6&_sid=71edf9a73&_ss=r