BTW, my '56 Merc Montclair 245 hp engine had the only OEM WCFB Merc used during those years. Vacuum secondaries, no duals. Lincolns also had them, but bigger venturis. No Fords.
Back in the mid 60s I drove my buddy's 57 chevy 2 door wagon with 283/4 speed and dual WCFBs, 30-30 cam etc...it was a joy to drive. The car had the "overdrive" 4.11 gears so it was really fast to about 90 MPH....was so cool to cruise along at about 60 and step into it....buuuwaaaaaaaaaa! Man, those carters would sing at high rpms! I never got over that power and sound. I have an old OFFY dual quad chevy intake and a pair of matched mopar WCFBs but they are the oddball 55 chrysler carbs with the external secondary vacuum cannisters on the side of the carbs...just the diaphrams for those damn things are 50 bucks apiece, not counting the rebuild kits for the rest of the carb...maybe I can block off the secondary stuff. The small venturies are great for a small cu.in. engine...like my 301 SBC.
I dont believe those are GM corvette carbs. The correct front carb has embossment for the choke lever that is not tapped. Throttle linkages are not GM, and idle speed screws look like chrysler(GM angles down towards intake). The counterweights on the p*** side look nothing like GM. Most of the vette lid numbers were 1299, and a bowl number of 049 or 1049.