The mag bearing can be purchased by itself. You unbolt the bearing housing and send them the whole unit, with platter in.
The reality is you bought the arm for $1500 to $2000 less then current market value for an earlier generation SME V. The table was free. I would either trade it in for one of their tables you like, or run it as is if the sapphire bearing plate is in good shape. If it has been cracked, then replace it with the mag lev option. It is going to be a fine sounding table as is, just fix anything that needs maintenance.
I own a Cosmos Total Eclipse, and it is a fine table. I first put a SME V on it, but to be honest, I was never a fan. I ended up with an Origin Live Agile, and it is my reference table.

