The first thing I think about is to look at Grand Prix, and Buick Century.
A web search with your part number 10249731 came up with them available from a GM vendor. I added 1 to my cart and got as far as shipping etc. so I think its a normally stocked part. Price was $39.20 each.
I'm not putting in any links because I don't know what the sponsor situation is on this forum, but have you not been able to find them on line?