jaharr01,
I agree with Lechuck, in that your compositional skills are a bit lacking.
I do like the plane / flag artwork a lot. Its very detailed and shaded excellently, with good composition.
But the card, and plain & huge USA, just do not match that level of quality. Its like dropping a powerpuff girl into Avatar.
Also, shapes and angles come into play. For example.. that huge rectangle shape is very pain and bland... and again, doesnt Jive with the other angles on the other artworks. Your eye gets sucked into it and stops dead. Many good artworks sort of lead your eyes in a smooth pathway. By angling the card, it makes the art more interesting and pleasureable to the eyes.. as well as can be made to match similar angles in the art or cabinet.
Aging does not mean just changing the darker colors either. Your card is "Mr.Clean" sparkling white. Like a George Lucus Star Wars CGI add in. Things that are aged, are dirty. White is often tinted to be more grayish, or yellowed... so as not to be so harsh on the eyes.. as well as to represent the filth that has collected on top of, and worked its way deep into the surfaces. Surfaces get micro scratches and it dull the surfaces, and so there wont be a lot of shiny reflections, as well as these collecting a lot of dust/grease/dirt...etc.. into them. Thus colors wont be as bright nor as reflective.
If your wife is asking for a classy woody... but you still insist on a small amount of artwork, I would stick to the 1st pics plane/flag art. Its very well done, very visually pleasing. Its not over the top, and should match a good wood finish fairly well.
If you wish to add other artworks.. try to find art that matches in those same color tones, as well as shading & artwork style.
For example, the plane uses blues for the shadowed colors. Its a very classic dual lighting style thats used by many skilled artists, to help pop the depth up, as well as add more interesting coloring aspects in there.
Some tweaking with Photoshops style color shifting tools, can help transform other art to match in color.. but... shading style, artwork composition, and stylized methods... could clash if not chosen and done well.
In such a case, you may be better off paying an artist to come up with some tweaks to your ideas. The stuff they may come up with, may please you, and your wife, 1000 fold over your efforts. As these guys have been doing this stuff their entire lives, and know all the ins and outs... as well as have a certain genius ... and unique way of seeing the world.
Im only a mildly decent artist, and I might still hire my art concepts out to a pro.
Just make sure to see plenty of their works in advance, and check into a handful of their references if possible.