A Japanese list of interenet sites that have paper models. There are some dead links, many sites that have already been posted here and a few sites that are new to me. Enjoy exploring.
ペーパークラフトを作ろう！ 無料でダウンロードできるペーパークラフト特集
https://www.ne.jp/asahi/yokohamahokubu/landmarkguide/papercraft.html