You have the 1500A Vulcan-88 like me. The "A" is different than the other 1500 models that they are referancing here. That engine guard will be very hard to find. You might try J&P Cycles, I talked to them a few months ago & they had one in a catalog that they could order. It was NOT listed in there online produts, but I was at the store and they showed it to me in a different catalog. If I remember right it was around $220.
J&P Cycles Customer Service 1-800-318-4823
97' Vulcan-88 1500A