I might get corrected but I've never heard of a "scraping level" but perhaps "scraping plate" is closer to what you're looking for.
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i make cnc gear making machines. one of the tests is to use a sensitive short level at least 0.02mm/m sensitive. actually the one we use is about 100mm long and far more sensitive than that. it is slid along every 100 to 150 mm specifically connected to a computer to show how flat or wavy over 1.5 meter long surfaces are. we find 2 types of error
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1) localized hardness variation in the metal that create high spots of 0.01 mm or higher
2) cnc mill servo was acting up and machine was going up and down while machining again sometimes greater than 0.01mm
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.......... in theory we could scrape the high spots but of course normally we just mill it another 0.012mm
not everybody in the world can afford expensive precision levels but i saw plenty in China all different types 0.02mm/m graduated vials costing $20 to $30 with scraped bottoms. it is normal in many places to see people doing hundreds if not thousands of hours of manual work including scraping surfaces as labor is much cheaper there compared to tools and equipment.
.......... if anything i had a hard time finding less sensitive precision levels. finding a 0.05mm/m level was rare if anything they kept trying to sell me 0.01mm/m levels. i saw many used machine tool places with hundreds of mills, lathes, grinders, edm, machines for sale. buying a used machine and having somebody recondition it by spending weeks if not months on it was not considered unusual.
...... many modern machines have precision linear bearing rails installed. The mounting surface must be verified flat and after the precision rails are install they are verified as flat, straight and parallel and perpendicular to other axises. besides levels we also use 0.002 mm dial indicators and granite squares as well as other tools
