The common ecu number's (this list may not be 100% accurate)
8 Valve (2E) 92 on Bosch Digifant :5WP 4 064 :::::::::::037 906 024 B
: 5WP 4 122 ::::::::::037 906 024 D
93 on : 5WP 4 151 ::::::::::037 906 024 AG
ADY 94 Siemens : 5WP4 160 ::::::::::037 906 025 A/E/
AGG 95 on Siemens : 5WP4 204 :::::::::::037 906 025 H
: 5WP4 256 :::::::::::037 906 025 R
16 Valve ABF 91-94 Bosch KE Motronic : 0 261 000 852/3:::::8A0 907 404
92 on Siemens Digifant : 5WP 4 066 :::::::::::037 906 024 G
Bosch Digifant : 5WP 4 133::::::::::::037 906 024 AB
95 on Siemens Digifant : 5WP 4 237 ::::::::::::037 906 024 AE
: 5WP 4 304 ::::::::::::037 906 024 BE
VR6 2.8 (AAA) 91 Bosch Motronic 2.7 :0 261 200 495/496:::::021 906 258 A
92 on Bosch Motronic 2.7 :0 261 200 491/492:::::021 906 258 CB
: 0 261 203 568/568:;::021 906 258 CH
92 on Bosch Motronic 2.9 : 0 261 203 116/117::::021 906 258 AF
94 on Bosch Motronic 2.91 :0 261 203 222/223 ::::021 906 258 BM
95 on Bosch Motronic 3.8 :0 261 203 968/969:::: 021 906 256
bold are apparently immobiliser one's (but don't hold me to that!)