Thank you all...I didn't think that the one that was on ebay that said it was a 15 91 and it had a belt was in fact a 15 91...but I wasn't sure.. I'll try and look up some of the models for the 15 and compair them..
pennycandy...I though that the 15 91 had a larger throat size then 6.5 thanks for letting me know the size of the throat, do you have enough room to quilt a large quilt on it? ...Thanks everyone for your help