Like Blade said, this is the place to go for the mods, Edge will translate:
https://wikiwiki.jp/pzfr/Steel%20Tank%20Add-on This will give you the STA 2.2 mod with all its extra content, plus the Japanese Community mod and Mission Pack. Follow the instructions on that page and enable in the exact order shown. After enabling, apply the 4GB patch to both shell.exe and starter.exe.
If you have an Nvidia card, Nvidia Inspector and the AA compatibility setting shown here (0x000012C1) will enable you to apply whatever AA setting you want; using NCP for AA corrupts the graphics. Apply to shell.exe not starter.exe.
You'll soon be trundling around in kit a bit more formidable than the Matilda!