Steve,
I got an original Pentax PH-S52 for my K 24/2.8 off EBAY a few years ago. I looked on EBAY for about 6 months before one turned up. Your A model takes the same hood. They show up from time to time and usually go for about $25.00. Way overpriced for what they are but there you have it. If you want an original hood this is about the only way to get it I'm aware of.
For what it's worth this is what it looks like on the lens.
Tom G