Rockwell Hardness Testers by the original US Wilson Company (then Acco Industries). Not a manual but a detailed explanatory Booklet from the 1980s describing how to determine which type of tester to choose for different jobs and materials with copious notes on the different types and methods to be used.

SAIMP (S.A.I.M.P.) JSS230 and JS205 Lathes Junior Special: Operator's Instruction and Maintenance Manual with Parts Manual as Detailed Sectional Drawings. Manual is in Italian.