Yes, that is a good suggestion and one that I will do.

I have checked under many spellings with no luck, but a different name is always a possibility.

I'll have to double check this, but I think that he would have been much too old to have participated in the Spanish-American War. Perhaps that was a son or nephew. I have not verified all the names of sons and nephews, but it would seem likely that one would have been named after the "old" Otto".