Early Esprits from inception until the 93MY SE shared exterior door handles with various other vehicles such as the Morris Marina, Austin Maxi, and Triumph TR7/8. The key blanks for use in these locks are the Ilco 62FG.
The ignition lock in this cars is shared with some early Toyota models. You can use blanks from Ilco: X174 TR40 or X211TR44.
With the introduction of the S4 changed from the Morris Marina door handles
and with it the old locking mechanism. These and newer Esprits use laser-cut
keys which have blanks in common with many Saab 9000 series models. Better
equipped locksmiths may be able to cut a blank for you. Otherwise, your only
option is to contact a Lotus dealer. The blank is a
Silca Italy YM27P Plastic Head Key Blank (Laser Key) for Vauxhall or YM30P