Dear David: From my experiences it is truly reliable, imagine that exist sevral/many SP-10MK2 that are still running after 25+ years and with many years to come with almost no " trouble ".
No, you can " migrate " from the MK2 to the MK3, you have to buy it this one.
Fortunately you can get easy the SP-10 service manual and a good local technician could fix your unit.
I own three SP-10s and works flawless, a very good TT quality performance: luck you already own it.
There are many SP-10s owners that maybe can/could help you in better way.
Regards and enjoy the music.
Raul.
No, you can " migrate " from the MK2 to the MK3, you have to buy it this one.
Fortunately you can get easy the SP-10 service manual and a good local technician could fix your unit.
I own three SP-10s and works flawless, a very good TT quality performance: luck you already own it.
There are many SP-10s owners that maybe can/could help you in better way.
Regards and enjoy the music.
Raul.