I just finished an upgrade job for a client, it was a stock STE in very nice condition given the following upgrades:
Before any modifications:
Replace the SN74S257N with SN74F257N U405 (Required for 32Mhz booster)
Reset circuit cap replacements
UBE TOS Switcher with fast ROM
Ultrasatan Micro-USB cable connected to Floppy 5v
Exxos 32Mhz STE booster upgrade & 8mhz/32Mhz switch.
New Exxos 110v PSU
Through every part of the incremental upgrades I informed the client with video demonstrations and photographs. The result is a very snazzy STE.And the rest: New 4700uf cap, Video capacitor upgrade, Install new RAM.