I think it is against postal rules to ship anything with fuel in it (of course, depends on your courier). You might want to add that comment to your complaint for a new one: you expect it to be pristine!
Build Date: July 18, 1966
I would DEFINITELY CALL Summit and tell them what you got and ask them what they'd like to do.... obviously you can't ship it back with fuel in it.... let them send you a new one and keep the other one.
In the description on the Summit carbs states 100% wet flow tested. So I think there would remnants of fuel left. I also had to return a Summit carb after I installed it and they said just drain it, there still had to be traces of fuel
I bought a FiTech EFI and it had smell of fuel in it, they also wet test each unit
* 100 percent wet flow tested and ready to run out of the box
* All aluminum construction for warp resistance and excellent calibration retention
* One-piece design that eliminates gaskets below the fuel line for leak-free operation
* Dual 30cc accelerator pumps (mechanical secondary models only), and annular boosters
* Interchangeable discharge nozzles and idle circuit restriction
* Exclusive color-coded vacuum ports for easier installation
* Thick base plate sealing surfaces
* High-flowing power valve channel with a valve guaranteed for a million miles
* Externally adjustable center-hung floats, clear-sight glass float windows
* Easy-adjust choke (electric choke models only)
Took took two tries for my friend to get a good Summit Carb from Summit. First one the top plate was warped and wouldn't seal, second one leaked from the accelerator pump. Third one was fine. Weird that they claim to be wet flow tested but they didn't catch two leaking carbs.