I say it is OK to take other's quilts to show and tell ... if possible ask the piecer if they would mind ... but I think as long as you give credit where credit is due it is OK ... FYI don't go in to great detail about the quilting ... ok to say I quilted this and it is a panto, custom or whatever but not OK to tell how many thread changes or things that promote your business ... show and tell is for everyone to get kudo's for a job well done.