Change Pilkor MKP 10nF with WIMA MKP 10 10nF Capacitor
Second verse, same as the first!  Your life is worth more than a few dollars saved on a junk-box capacitor!!!

Order in the proper Class Y (10nF/250VAC) safety rated capacitor, install it, and be done with it.  Sure, it might cost a few bucks, and a few more bucks to ship, but consider it an investment in peace of mind that your welder won't turn around and zap you some day!