Ray.
You sound a lot like me, little bit different taste in music, but still in the same ballpark (I enjoy bluegrass and acoutic blues) and like you, mostly listen at a low or moderate volume, and yes, I'm a bit past "middle aged". Chances are you might want to keep your speakers, as if you're like me you appreciate a warmer sounding speaker than a more analyical one. Of course, the only way you'll know is go out and listen to some different speakers, and don't be surprised that what you'll hear while sounding different might not necessarily sound better. One question though, what is your source component, CD or vinyl, and are you thinking about changing or upgrading that? I'm the sort of person who feels that the source is the most important component, as nothing down the line can improve upon what is orginally delivered. If you got a good source component , and you like the sound of your speakers, perhaps upgrading your amp, may be all you really need. Remember the most important thing, is that your system satisfied "your ears", and delivers "your music" the way you want to hear it, and the age of it really doesn't matter. I have many friends who's systems would be considered older or "vintage" and they're still getting quite a bit of enjoyment out of them. Nothing wrong with an older system if it sounds good.