Sorry - there's a bit more. I thought I had some more details somewhere on the 1-11-510 fleet and I've just found a sheet of A4 with the entire fleet exit listed (it's dated in March 93 so doesn't have full fleet exit details for the ex-BCAL aircraft which were mostly still flying by then). I doubt this will be on the internet anywhere as it's long before the days of Flightradar24 and the info was from a log kept by the F/O who was the BA 1-11 Fleet Technical chap based at BHX at the time.
One or two of the details here contradict postings above - so I'd take these as as the definitive info. Hours and cycles are total airframe time as at the date of ferry to BOH.
G-AVMH msn 136. Delivered 11Jun69. Last service 23Nov92 HAM-BHX. Ferried 24Nov92 BHX-BOH. 40278 FH, 45190 cycles.
G-AVMI msn 137. Delivered 01Apr69. Last service 14Nov92 GLA-BHX. Ferried 18Nov92 BHX-BOH. 40966 FH, 46151 cycles.
G-AVMJ msn 138. Delivered 21Aug68. Last service 06Jan92 LHR-BFS. Ferried 13Jan92 BFS-BOH. 40483 FH, 45720 cycles.
G-AVMK msn 139. Delivered 13Sep68. Last service 02Dec92 GLA-BHX. Ferried 04Dec92 BHX-BOH. 41033 FH, 45797 cycles.
G-AVML msn 140. Delivered 04Oct68. Last service 12Jan92 DUS-MAN. Ferried 13Jan92 MAN-BOH. 40002 hours, 45102 cycles.
G-AVMM msn 141. Delivered 22Oct68. Last service 13Jan92 CDG-GLA. Ferried 13Jan92 GLA-BOH. 39713 hours, 44446 cycles.
G-AVMN msn 142. Delivered 15Nov68. Last service 09Aug92 FRA-MAN. Ferried 10Aug92 MAN-BOH. 40942 hours, 46177 cycles.
G-AVMO msn 143. Delivered 22Nov68. Last service 18Dec92 CDG-GLA-MAN. Ferried 29Dec92 MAN-BOH. 41336 hours, 45788 cycles.
G-AVMP msn 144. Delivered 04Dec68. Last service 07Oct92 CPH-MAN. Ferried 09Oct92 MAN-BOH. 41747 hours, 47451 cycles.
G-AVMR msn 145. Delivered 02May70. Last service 13Jan92 DUS-MAN. Ferried 13Jan92 MAN-BOH. 37823 hours, 42553 cycles.
G-AVMS msn 146. Delivered 10Jan69. Last service 31Dec92 GLA-BHX. Ferried 05Jan93 BHX-BOH. 40934 hours, 45269 cycles
G-AVMT msn 147. Delivered 23Mar69. Last service 30Sep92 CDG-MAN. Ferried 01Oct92 MAN-BOH. 40267 hours, 44993 cycles.
G-AVMU msn 148. Delivered 19Mar69. Last service 16Dec92 DUS-BHX. Ferried 19Oct92 BHX-BOH. 40279 hours, 45540 cycles.
G-AVMV msn 149. Delivered 10Apr69. Last service 31Jul92 FRA-MAN. Ferried 01Aug92 MAN-BOH. 40512 hours, 45563 cycles.
G-AVMW msn 150. Delivered 13Apr69. Last service 24Dec92 MAN-MAN (Santa special). Ferried 30Dec92 MAN-BOH. 40611 hours, 45254 cycles.
G-AVMX msn 151. Delivered 20Jun69. Last service 13Jan92 LIN-MAN. Ferried 13Jan92 MAN-BOH. 38020 hours, 42549 cycles.
G-AVMY msn 152. Delivered 09Jul69. Last service 13Jan92 BHX-GLA. Ferried 13Jan92 GLA-BOH. 38557 hours, 42922 cycles.
G-AVMZ msn 153. Delivered 12Aug69. Last service 31Oct91 BHX-EDI. Ferried 04Nov91 EDI-BOH. 38376 hours, 43290 cycles.
So looks like the very last 1-11-510 service was 31 December 1992 GLA-BHX by G-AVMS. One suspects this wasn't planned as such as the Santa Special by G-AVMW on 24 December at Manchester is listed in print books as the last service.
The plan was for G-AVMO to be preserved (and contrary to earlier posting, pleased to hear it survived the chop at Cosford) and G-AVMU at Duxford, as occurred.
G-AVML, MM, MR, MX, MY and MZ were all painted into Okada Air colours at Bournemouth but never went to Nigeria (which is where two of the three 1-11-539GLs had gone in July 1991, the other - G-BGKE - going to GEC/Ferranti as then was, later Qinetiq at Boscombe Down). European then acquired the lot.
By the time of the last 1-11-510 service, the only other -500s to have left the fleet were the three -539GLs above and G-AXLL, G-AYOP and G-AZMF. The others (G-AWYR, YS, YT, YU, YV, AXJK, AXJM, AZPZ, BJRT and BJRU) were all still flying in March 1993 when the list I have was finished. I don't have the same details for the -400s, of which five had gone off to Birmingham European / Brymon European by then.