Sorry for the delay. Aah spring is in the air.
My Montbell pad has a compression type strap for rolling it up (which I never use for that purpose), but it also works for holding the pillow in place. I actually take the GG sit pad from my Mariposa and attach it to the compression strap and put my pillow on top, along with a cut down GG torso pad for lower legs and feet, this make a full length sleep system for under 14 ounces, although I am kinda short, which is sometimes a good thing!. I will try to get a picture this weekend. My home-job is pretty rough, but functional. I think using lighter tape would work okay. I just happened to have a small roll of Gorilla tape on hand. The cool part of home made gear is total personal customization, so you should be able to make your pad to work with the Montbell.