I didn’t reply sooner because I also couldn’t find the expansions you are looking for. Pacific Theater is bound to get a reprint someday soon, because it has been out of print for a while and it’s part of the army packs. As for the other ones, I have heard several times from facebook groups to not expect a reprint of those. This is not to say they cannot be had for some amount. Depending on how much you’re willing to spend, you can browse boardgamegeek for entries for each and every M44 expansion. Inside each expansion page there’s a “Market” tab that will show you people around the world willing to part from it for some amount of money. Some entries will be at a reasonable price (but consider potential international shipping), but others ask for an outlandish amounts. You decide how much you pay for them.
Campaign book 1 is available as a pdf download for around $15 on days of wonder website. I’m sure your aware of the reprints of several expansions, if not
, I’d advise grabbing some soon as they’re selling out pretty quick.