I don't think there were T or MH marked cases either, the V was the exception. Marking a case T or MH would add complexity in both assembly and storage and reduce flexibility, to no benefit to Heuer. I am slightly surprised they differentiated the 773x manual cases though I suppose it's an additional way of tracking volumes of each movement.

So why make the exception for the Viceroys then? I imagine it's because it was such a different sales channel they wanted to keep them permanently separate, both in their records and physically. Having a V permanently marked on the case allowed that more easily than keeping records of the dial differences between a black V and a black MH dial.

There are simple explanations for mismatches ex-factory. If the demand is underestimated and insufficient V cases were ordered (which I have a vague recollection of having read here), there was probably a temptation to fulfil orders using plain (i.e. not marked with a V) 1163 cases. The opposite would leave excess V cases. I would have thought they would have had a better handle on it by the time of the 11063 and 11603, but who knows?!

The upshot is, if they ever mixed and matched ex-factory back in the day, it would be very difficult today to distinguish between that and a watch put together from several today. So it's perhaps best to deal in expectations - we expect a Viceroy dial to be in a V case and an MH to be in an 1163 case, then apply the usual caveats re checking details and buying the seller.