Well, the best candidate I found this far was actually written Olof by the priest. He might prove hard to investigate though, since his father is a "wanderer" from another parish. https://sok.riksarkivet.se/bildvisning/C0041733_00014#?c=&m=&s=&cv=13&xywh=16%2C2360%2C3905%2C2126 (https://sok.riksarkivet.se/bildvisning/C0041733_00014#?c=&m=&s=&cv=13&xywh=16%2C2360%2C3905%2C2126)
With the soldier name Malm I'm tempted to look for Ola on Malmön though, but the church books in Askum socken are lost to a fire in 1898.
Thank you again! I see that Ivar Berg is a "wanderer," but it looks like perhaps he was a wandering sailor. I did find an Ivar Berg at http://www.soldatreg.se/, but he died in 1789--six years before Ola Malm was born. The search continues...