Could be... I just had a recollection that I can't confirm that HM instigated it. I might have dreamed that...
OTOH I was just going through Racing Icon's diary of the restoration of AMGT40/1 (http://www.racingicons.com/gt/amgt40-1/amgt40-1-5.htm ) which for a brief time was a MKIIB, kind of, and they refer to the dash as "the Holman Moody MKIIB dash and wiring" although arguably that's simply because HM were the ones that did the conversion from MkI to MkIIB.
Alan cannot get to the link. You mentioned AMGT-1 which was the chassis number of one of Alan Manns MKI lightweights from 1966. It was a small block and never a MKII. Alan Mann wanted to race these instead of the MKII at Le Mans . A test with Jackie Stewart and Graham hill established their preference for the MKII. The 1965 cars GT106 and GT107 were 7 litre big blocks further redesigning and test led to the 1966 MKII. The MKIIB in racing terms was virtually obsolete in the 1967 season. They were used as rabbits to try and break the Ferraris (Paul Hawkins MKIIB) and backup for the four MKIV's in the race.
I suppose there might have been cross corporation being the three teams Shelby, Holman and Moody and Alan Mann. But I thought the Alan Mann cars were built by the Alan Mann mechanics. Thats why they had their own chassis numbers XGT 1,2 and 3 (number three not being raced) for the MKII and AMGT1-2 for the MKI lightweights that were not used after the 1966 Le Mans trial. When Roy Lunn instigated the 1965 MKII program the protype car for the 1966 MKII car was called the X-car. This might explain Alan Manns chassis numbering. The only other X car was the X-1(chassis GT110) Can Am entry also 7 litre big block. I have seen P1046 the 1966 MKII winner being converted into a MKIIB with the MKIV's dashboard. Why would they uprate an obsolete car to test a new dash board when they had 1966 MKII still available to test on? Also Alan Mann was not invovled in the 1967 race for Ford.
Regards Allan