Crap... I forgot all about this thread. I did find my manual, though, and have a PDF of it I scanned. Anyhow, for GVP A1230 Turbo+ (original) you are correct, the only change is remove J5 for 16MB SIMMS. Also, largest sized SIMM must go in Slot 1.
A1230 Turbo+ (original) Jumpers:
J1 - ON - 68020 / (OFF - 68030)
J2 - RESERVED (ON)
J3 - RESERVED (OFF)
J4 - RESERVED (OFF)
J5 - (ON - No 16MB SIMMS) / OFF - 16MB SIMMS PRESENT
J6 - RESERVED (OFF)
CN4 - RESERVED (OFF)
CN5 - (ON - 4k REFRESH DRAM 16M) / OFF - 2k REFRESH DRAM 16M
CN6 - RESERVED (ON)
CN7 - RESERVED (OFF)
(.)=DEFAULT
So, PM me your email address, if you want a PDF manual for any of the following:
GVP A1230 Turbo+ (original, no expansion port)
GVP A1230 Turbo+ Series II
GVP A1291 SCSI Kit Performance Series II (SCSI expansion for A1230+ Series II)