In less than 45 seconds, I found 2 sources online for the original carb.

http://shop.ebay.com/i.html?_from=R4...All-Categories

http://tewarehouse.com/WT-76-1

That engine commonly used the Walbro WT-76 / 76A but any number of carbs could easily be adapted. How about the carb for a DLE-55 for example? You would have to convert it to internal pulse port but that would take less than 5 minutes to do .... and they have a reasonable price. Also, the Brisson carbs had linkages that were bolted to the stock carb linkage so there is nothing special about the carbs in that area. You have many very workable choices.

I have bought these carbs from the E..Y source above and they are perfect as advertised. Excellent source of parts and carbs.