Bringing back an old thread, but this helped me with some research today and wanted to provide current resources. In the researching I found this catalog which outlines the Lucas Windshield Wiper and Screenjet parts including the individual service parts.
https://www.jaguarforums.com/forum/a...enjets_etc.pdf
On page 44 you'll see the Screenjet parts, and for the single jet for 289 cars should be the following parts:
Nozzle Assembly - 295112
Nozzle - 295006
Upper Plate - 295067
Lower Plate - 295068
Gasket - 295268
Spanner - 770652
Screw - 186147
For sourcing sprayer nozzles, as had been mentioned previously Four Ashes Garage is remaking the nozzle and according to their website are working to remake the upper plate currently.
https://www.fourashesgarage.co.uk/as...ts-gasket-kits
Another source, on eBay user captainrobin is selling NOS Lucas assemblies including nozzle, upper plate, lower plate, gasket, and screws. I just placed an order for a set, so will take a couple weeks to make it across the Atlantic. Robin was able to share a picture of the assemblies and was quick to respond to any questions.
eBay auction listing