Here's an update for an old website, the Dougram Bromley heavy mecha transport truck is now available, but check out the other models too.
https://papertoybox.hateblo.jp/entry/download/download1
The Dougram Mavellic (not a typo!) heavy mecha transport helicopter can be found here:
https://web.archive.org/web/20190330...maberikku.html (click the bottom link to the Home directory, then use the translate function to find the Space-time Flying Lesbians 2007 model!)
For those unfamiliar with Fang of the Sun Dougram, it was a 75-episode 1980s military anime (similar plot as original Star Wars) that featured plausible mass-produced combat mecha as opposed to the one-off super robots of early anime like Mazinger and Voltes V. With limited ammunition and endurance they needed support units for transport outside of combat, hence the transports above.
Many of the mecha designs were reused in Battletech/Mechwarrior board/computer games like the Shadow Hawk (the titular Dougram), Wolverine, Griffin, Scorpion, Thunderbolt, Goliath and Battlemaster. Some of these have been done as paper models, do a search for Mechwarrior papercraft.