Hello @glm911 and welcome to these shores.
You have a pair of excellent speakers and your amplification, while dated, is a very good vintage!
1) In your shoes, I would begin with an external phono for your TT. 1b) I would then check the usefulness of a superior cartridge.
2) Following that I would check the room acoustics and improve them as much as you can: there’s no point in improving a system you cannot hear!
3) Third, I would look into getting a ultra-high precision preamplifier. (Your power amp is quite good, even by contemporary standards (IMO). You could consider refurbishing it).
Of course 1 & 3 can be had in the same device. Purchased new these tend to be expensive. Used prices are much more attractive: a CAT Ultimate (tube) w/ phono is excellent and can be had for around 5k used. There are others, including ZOTL Ultralinear.
The above are tube based.
Regarding SS, Pass (mentioned above) is an excellent designer and his equipment is (intentionally) warm sounding. There are others, more revealing, and that match well with your kind of speaker: DartZeel, Symphonic Line...
There are of course, many choices and everyone here will offer at least one! If at all possible, it is worth trying out equipment in your system before you invest. You might find that your system is OK after all!