A lot of the hard to find kits like that one make for some interesting auctions on eBay. Another option is to place a want ad in the classified’s of one of John W. Burns bi-monthly publictions… I forget the name. Model Collector’s Clerainghouse maybe?
In my quest for some OOP vacforms I always see that kit on E-bay, at least twice a month. from the Models category search descriptions and you’ll get one. Good Luck!