Yes another 235 6 cyl problem

Well, I just installed a new distributor on my 235 six. Every place I checked including some of our sponsors had them for around $80 to $90 plus $30 or more core charge. They were all from the same rebuilder, but one place, AutoZone had them for only $41 and a $10 core charge so I got it there. I don’t know how there can be so much difference in price for the exact same item, and as I said I checked and they are ALL the same item from the same rebuilder. Anyway, when changing it, I found my vacuum advance module was bad. Doing a search for one, I found only one place that said they sold them and they were out of stock, and the price was sky high as far as I’m concerned for what it is and what it cost for other distributors. I know another person on here is looking for one also. Does anyone know how to modify one from something else to work or where to get one? With so many of these on the road (I think all 49 to 62 Chevy 6 cyl engines take basically the same distributor) you would think someone would make a replacement one cheap. The car seems to run fine with it broken, but I would like to have a working vacuum on my engine. Thanks for any input. By the way, ebay has NONE and also, I don't want a used one that might be on it's last legs. Just my luck and it would go out as soon as I installed it.