over on slantsix.org and slantsixdan has a thread about how to fix it using a gas fill pipe restrictor that can be purchased at
www.pciinc.com/index.php/gas/fill/pipe/restrictors
this place. You'll want the smallest one for the early A's
there is even an instruction sheet on how to do it somewhere online .
I just haven't been able to loctate it yet. ahh here it is Gas sentry.
View attachment 1714548844
or here for something you can read instead of squinting at
All sizes | InstallingFuelTubeSpillageEliminatorIn65Dart | Flickr - Photo Sharing!
I just got mine in the mail. it took a while for them to send it , but looks to be worth the hassle of installing it just for the paints safety.