I too am wanting to add a front dinette...except in our '64 GlobeTrotter. I have been collecting photos & websites that show them a "stock" for a '60's model and came across this site:
Dinette Plans
Although this is an older model than yours, the idea is still the same. Be sure to highlight the page as the text is white-on-white & does not show up.
The biggest difference would be in the width of the trailer - 8' for the '64 & I believe 8'-6" for yours...
Anyway, it's a starting point....
Shari