carbcarburetors

I've taken apart my carbs to rebuild (due in part to a fuel leak). Clever previous owner hadn't replaced all the bolts and had placed two gaskets in one of the bodies and none in the other. Anyway the bolts are all pretty rusted out and a few other parts will need replacing. My question...

I've always measured float level with my electric caliper correctly based on reading many threads here (making sure to measure it from the inside of the carb where the gasket is placed as recommended here ), but I thought I'd grab this tool I saw a couple others on the forums got or made to see...