Got A Turntable...What Next?


I inherited my deceased dad's vintage TT , speakers and
large classical vinyl collection. He died in 92 and the stuff was still in his basement in perfect condition just
like he left it.I am now taking care of my 87 year old
mom with Alzheimers and decided to get his rig back up and running. I brought over an old receiver with a phono stage
and a friend lent me an AT cart just to see how things sounded. Now its three months later and the system has grown with used gear as shown below.

Thorens TD-125 w/SME 3009 II
Shelter 501 mk2
PS Audio GCPH
Decware SE 341.2 (6 watt) tube w/ NOS Amperex Holland
Altec Lansing "Laguna"
http://www.vintage-audio.com.ua/en/cat/68/1469.html

I am really enjoying the vinyl experience again, have a cleaning machine and i am doing it the right way.

My questions are:
I want to upgrade to a better sounding system.....should i keep any of my present gear? I feel the speakers are the weak link, they have a wonderful mid-range but lack a little in high end and bass.
Any opinions? My budget is 8-10k. Used gear is fine.
I listen to mostly classic rock, blues and some classical.
128x128edtyre
Restock:Mine has a removable headshell.
The first cart i tryed was the AT440ML. The Shelter has much better sound its like night & day.
The 3009 with removable headshell is borderline ok. Given the effective arm mass or 9.5g and specs of the Shelter (8.1g, 9cu compliance) you get a resonance frequency of about 12.5Hz just a little outside the ideal range.

The Shure V 15 VxMR is very often matched to your arm (and difficult to get), but the Shelter is a very good cartridge and even with a poor match may be better than many MM cartridges.
Just my 2 cents, I would focus on the source first before anything else. Of course if the amp is weak than that should be taken care of, other than that, one will never know what the system is capable of until the source is optimized.
From my experience, I didn't know what my speakers were capable of until I got my vinyl rig greatly improved!
update:

Recently purchased a Shure SME 3009 II IMP
with Incognito wiring from another Agoner.

This 500.00 upgrade has done wonders for the overall sound.
Have been listening for a while now, what a difference from
the other SME arm and 1973 wiring.

Still looking for improvement, will audition a few more powerful tube amps next. The speakers are staying, but i'm
not so sure about the TT,arm and cart... i think to get to the next level i might have to go with a more modern set-up.