My first WAG was letter opener. Good luck swastika as opposed to Nazi Party which I find odd since yours is dated to '39 and the NSDAP adopted the design in 1920.
Not sure what it is, but I don't see why it couldn't be Nazi related. Texas had more German POW camps than any other state (including 1 in Abilene) and housed nearly 80,000 prisoners at one time. On the other hand, I can't see them letting prisoners wander around with a potential weapon like this either. Could have been a spoil of war that some vet brought home as well.
The Buffum Tool Company of Louisiana, Missouri manufactured "High Grade Tools for High Grade Workmen" from about 1909 to 1922. The Buffum company's trademark was a swastika with right facing arms. During World War I it made bayonets and airplane parts. The company's logo was the "Good Luck/Blessing/Swastika Cross" and many of the products, sold nationwide, had "the good luck cross on them."[51][52]http://en.wikipedia.org/wiki/Western_use_of_the_swastika_in_the_early_20th_century#cite_note-50
Yes, it is a scraper for fitting babbitt bearings, The edges would have been very sharp. I have one that size in my set. Some of the old engines,like the one in my avatar, would have babbitt bearings that would have to be fitted/scraped when they were replaced. Tony