Of course we do have to think that these small town gents were not used to visitors, being under the glare of staged lights and on camera. If you read the credits the tripod-mounted camera (35 mm!) and lighting gear was professional stuff. It wouldn't have been a 'business as usual' day for these lads. The incentive for the subjects to 'spruce it up a little' in depicting an otherwise dull and monotonous routine must have been there. Lighting a pipe off a hot piece of steel, overly vigorous wedging and creating generous volumes of sparks are small ways of accomplishing that.
Or it could just be that a couple of guys pumping out axes the old way long ago did not use kid gloves. They new exactly what had to be done, and how to do it correctly and quickly.