After some iterations of detaching the side skin and working on the front longeron with the die grinder, I finally managed to cut back the longeron to 3/4 inch from the front side of the skin.

Then clamped the front side of the longer to the side skin.

Drilled the 7 holes to #30.

It's not a big deal, but knowing that these are the holes that attach the engine weight to the fuselage gave me some stress to do it perfect.

Fortunately, all went very well with nice holes as a result.

Next step was to mount the firewall to the fuselage assembly. Clamped the steel brackets to the longeron.

Draw a centerline on the firewall stifferener. This is where the second line of holes from the bottom skin will match and will set the correct distance of the firewall plate to the F704 bulkhead.

Took a long on the other side and verified positioning of the longerons in relation to the firewall position. Boy, this is tight. When firewall is in place, I probably still need to take of some hundreds of an inch to get it perfect.

Also clecoed the bottom front plate in place. This is starting to get really cool.

Shot from the inside.