I took a look on my STX, there is two power regulators (one for 12V and one for 5V):
5V@1A is a AZ7805D (TO-252) marked as U20:
12V is a 7812 (TO-252) marked as U24.
X1: 24.576MHz @ 5V (so called crystal or TCXO).
I'm planning to change OPAs too.
1st option LME49720HA+OPA2111SM.
2nd option 2xOPA-Earth + 1xOPA-Sun
And of course the crystal.
Last mod would be the capacitors to Premium type (better than Fine Gold).
About the OPAs, what's better? 1st option or 2nd one?