Tell us about yourself!
Hopefully the last "broken link" I've found, I clicked them all today. Step 6, 8020/3382, 1/4-20, T nuts, the correct link is: https://8020.net/3382.html
The 20 Teeth, 3 mm bore, 6 mm width idler pulleys used on the X and Y axis are "currently unavailable" according to Amazon, using the above link(s). I found these and they appear to have the same specifications.(https://www.amazon.com/UTL-Timing-Bearing-Suitable-Printer/dp/B07FKK8JLN/ref=sr_1_8?keywords=gt2+20+teeth+idler+3mm+bore&qid=1552013545&s=gateway&sr=8-8)