Seville 81 368 8-6-4 ecm eprom source ?

I am new on this news group, I own a 81 seville with the 368 8-6-4 and the problem is :
The engine doesn't start. When I try to enter in the diagnostic mode, the display shows ".." and stay
on. Reading the DFI chart #1 from the shop manual, the culprit is "faulty ECM or faulty EPROM. On my ECM the label is gone , but after an inquiry I know I can use an EOM 1225120. So I can replace the ECM. But as I can't discrimante between ECM and EPROMs I would replace also the two EPROM. The problem is since today I am not able to locate an EPROM source. Here under the whole information I have about :
VIN : 1G6AS6990BE696709 EPROM transparent socket DELCO 7977FT N 326553 EPROM green socket DELCO 7978FT N326957 NB : I Think it is an export version (?) because the car is labelled "GM FRANCE"
Thanks for your help, I am a little bit desperate. I hope my english is understandable.....
Didier Hardy
Seville 81
  Click to see the full signature.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.