As Smartdog said, there are dozens of topics along these lines already hashed out, and I think you've already received a good variety of responses here too from some very accomplished makers. I wanted to make a quick note about the idea of a "working man's gun".
A gun was financially well-within the means of anyone who was allowed to own one, and every farmer had one for predator and pest control. Rifles, made here in the colonies, generally cost several times what an imported farmer's fowler would cost, and they were often owned by the poorest people on the frontier for hunting deer and other big game. Based on surviving examples and period documents, these were not undecorated, and are often described with a wood or brass box, carving, and curly maple stocks. There are perhaps half a dozen rifles we know of that were captured by British officers and saw almost no further use once in royal English collections. Some of these are about as well-decorated as 18th century American arms get, and were possibly being used by riflemen in battle when captured.
It's next to impossible of course to say exactly who was using them, or where they were captured, and we have to consider survival bias too - were they picked up because they were the nice ones?
If we move north to New England fowlers - we have a surprising number of surviving guns with known rev-war provenance, that also have quite the range of decoration on them.
Back to tool marks - every un-molested American gun I've handled from the 18th and early 19th centuries has tool marks - drawfile marks on the barrel and lock, scraper marks in the stock, chisel cuts not fully cleaned up in the background. Not sloppy (well, some are), but clear evidence of haste. I personally find this to be their charm, with an endearing level of quality and decoration. That was an acceptable level of quality for them, and there are many 21st century buyers that don't care for it on their new-made guns. One of my next projects is a 1740s English fowler, and the original I'm basing it on had not a tool mark to be seen (though you can guarantee the underside of the barrel is covered in file marks).
-Eric