TBM,
If the bit you are after is the right angle drive and it is the same as a Ford 3 rail box then look at lotus dealers, it will be the same as an Elan or +2. Paul Matty has them listed, not cheap at £74 +p/p +vat .
Here
https://paulmattysportscars.co.uk/product/speedo-right-angle-drive-4-speed/I have one in pieces that we could come to a deal on or you could borrow my spare but it MUST be replaced or returned some time. PM me for more dtails.
Edit, If the one I have suggested is the correct item then there are plenty on the bay for less money. Could you post a pic of the item you require.
Cheers
John
