This is a NIT really, because this works, but since the URLs are the same, we could make this a single rule:

```apache
RewriteRule ^/en-US/firefox/(vpat-[\.1-3]+)(?:\.html)?$ http://website-archive.mozilla.org/www.mozilla.org/firefox_vpat/firefox-$1.html  [L,R=301]
```
I think that would work.