MC is (I believe) college student (maybe post military?)... somehow goes to an alternate world, thrown into the past, or something similar...can't remember details. All I remember is that at some point he gets a chance to return to his home, goes there, but just to catch up with his family and collect items/books/etc needed in the place he ended up and plans to return there. I believe he pays for the items by selling some gold coins or something from the place he ended up. Think he goes with a female from there whom he is involved with so his family (especially his mother) can meet her. They eventually return with the new items to help improve their lives in the new world/past time.
This is all I can remember for sure from this story. It might be a small part of a story that I remember other bits of in better detail but where I can't remember that they are connected ... or it could be the only part I remember for this story. Won't know which is which unless some kind soul is able to identify the story for me from the little bit of info provided. Thanks.