Great project, Johnny! I'm sorry I missed it until now. Your natural metal finish is coming along nicely.
Yes, these Monogram multi-engine aircraft kits hold up well today. They represented a new level in detail, for their time, and still were kits that a modeler with little experience could build and enjoy doing it.
Yours was popped in '91, but the kit was already about 15 years old by then.
As for preventing tail-sitting, I'm sorry I'm late to this party, but I'll offer this tip for future builds: if you're putting the model on a base, then you can dispense with weights, and use a fine bolt installed in the nosewheel instead. That's a tip from none other than Shep himself-he noted it in his P-61 build, and it always works well for me.
Regarding the PE barrels and cooling jackets-are the jackets that fragile, when you fit them over the barrels, or does the combination of the barrel and cooling jacket make for a more rigid part, less vulnerable to bending?