A 16 circuit ONS line card for my Mitel sx-50 recently failed, and I have noticed that I have only lost 4 phone lines. The 66-block the card is connected to is marked out for more lines, but they were never used. Can I replace the 16 circuit card with an 8 circuit without having to worry about programming or re-wiring? All of the lines which are in use are at the top of the block, so I assume they are connected to the first few pins which connect to the card (if this makes a difference?).

Of course this means I am in the market for such a card. So let me know if you have one for sale.