Hello David,
You need to find a Toyota dealer, failing that you need the main importer in your country who will also import spares, when you say you have disassembled the part that moves up and down I take it you mean the needle bar, if you have and if you have not markes the exact position that you removed it then you will need to retime the machine when you assemble it.
drivewithken@blueyonder.co.uk, May 2008