I know I've read on here about restringing these pull down shades. Those whom have, do you remember the diameter of string you used. I've gone to fixmyblinds.com site and their string sizing scale procedure I'm skeptical about.
I restrung two last Fall, here is my thread on it with a link to the repair kit I purchased. Turns out all I needed was the string, not the kit. But I have no clue about the diameter, perhaps a PM to one of those who responded to my thread may know what string to buy.
I restrung one of mine last month, I went to my local RV shop (Richardson's RV) and bought the kit they had. Only 1 kit there and it worked. As you said, I saw some sites that asked for the size string and it confused me. But only having 1 at the shop made my choice easy!!
this is the one I used http://www.ebay.com/itm/United-Shade...a94e15&vxp=mtr
If you are born once you will die twice
If you are born twice you will die once