"I have heavy curtains on the back"...
Do you mean behind the speakers? If so try taking them down. You should not be deadening the back wave from your speakers. Diffusion/dispersion is what you are after. You can use something else to disperse the back wave.
FWIW in setting up dipoles/panels/electrostats 3ft into the room is not going to give you optimum imaging. There will not be enuf delay between the original signal and the back wave signal. For this reason 5' is usually optimum.
Can't tell where your listening position is but I assume it is triangulated and about 7 to 8 ft back from the plane of the speakers. If you put the speakers on the short wall out into the room about 4 feet, about 8 ft apart, and your chair about 4 ft from the wall behind the chair, with a dispersive materiel on the wall behind the speakers, you should get great imaging.
I realize you may have decorative/domestic considerations, but I think think might be a set up that would work well if you could do it (or at least try it).
P.S. I don't think what you describe has anything to do with equipment. If you had good imaging before you should have it again, even better, not worse. Note I'm not saying you can't get better imaging with better stuff, but if I were you I wouldn't go there until you have optimized set up. Stats and panels can take a while to set up properly. It took me nearly a year of playing with Quad 63's 'til I got it right (mostly due to inexperience and a lack of good advise from others).