How difficult it is to translate !

I've been trying to translate a book written by an American jounalist since about a year ago. The title is "Chippewa Chief in World War II". It is a story about an American Navy airman whose fighting plane crushed down in Hokkaido Japan, and survived hiding in the mountains. His name is Oliver Rasnussen, and he was born in native American's reservation. I was interested in how he had grown up there. He lived in the wild land in the reservation, just as I lived in the wild land in the mountains in Miyagi prefecture during the war. And more than that, the place where his plane had crushed down was in the mountains of the foot of Mt.Tarumae,a volcano in the suburbs of Tomakomai city,just close to my house.
I have finished translating as far as p.163 of the book of 190 pages. But I stopped it,feeling difficult, because there are a lot of technical terms of the flight navigation and navy jargons. The time was during world was II, more than 65 years ago. I have tried to look up those words in dictionaries and on the internet, but in most cases, I couldn't find them. Can I continue, and complete the translation? How can I find anyone who would help me.