Macau FDC Casino Issue

I am looking for a source for a specific issue of Macau Stamps: SC#551-554,the Casino issue (9-30-87). I have tried all the web browsers, Google, eBuy, even Amazon. I have tried Macau Stamp Dealer, Macau FDCs, and others to no avail. I have looked into PRC dealers, Asian Dealers and find the stamps but not the FDCs.. Any help would be appreciated. (I have the stamps)

Found these 2 sets on ebay, no idea if the price is any good.

https://www.ebay.com/itm/127193262753

https://www.ebay.com/itm/3886350068...u+fdc+casino

thanks Mike: I did see these some time ago. They appear to be the same item by 'different' seller. The postmark is barely legible (& that's with a high resolution magnification. ) The prices are substantially different which makes me suspect an issue with the validity. I'll wait for Boston 2026 & look for Asian dealers . I'm hoping for a WW FDC dealer that might have a simple envelope FDC (addressed or unaddressed.) again thanks for the effort. I'll continue my review of dealers or web searches. (I'm actually thinking about asking one of the casino magnates in Macau for a favor, but haven't built up enough nerve yet)