I experienced this exactly. One of the most capable and popular combos is the Markbass CMD121P which is a NY121P cab with a Little Mark III head squeezed in at the back facing upwards. This reduces the internal volume of the combo by that of the amp and surrounding timber. When I directly compared my CMD121P to my seperate LM3 and NY121P the combo didn't sound as full convincing me the extra carry was worth it. I now have two NY121P as my lightweight medium duty rig.
A STD102HF would be the ideal extension cab for your combo. With the combo head able to deliver its full 500 watt output you will have enough power for any reasonable gig either inside or out. Festival stages should provide PA support and your rig will be plenty for stage volumes.
Strictly speaking Fenders are dated by when they are assembled, which in this case must have been after the neck was produced in 1961. Beautiful refinish, good luck with your sale.
I think the better question is how old is it please? Date of production is shown on the rear label. Perhaps you could delete the two stock photos and add some more of the actual head.
Is there a reason why the A and D string machine heads aren't symmetrically spaced from the centre line of the headstock? I have never seen (or perhaps noticed) this on a 2 + 2 headstock design before.