N O P
To finish off looking at the Highland Railway wagons before 1896 there are only three more types to be covered and there were only a single example of each type (probably). They also each had six wheels.
Type N was an 18' long, six wheeled flat wagon with low folding sides and ends, described as an Engine Wagon. The diagram book gives its HR number as 2147 but there is some confusion about its LMS number as 297232 or 297233 are quoted in different sources. Both sources agree that the LMS recorded it as being built in 1875. As you would now expect, having read this far in the thread, it has the usual Jones features of narrow headstocks and inverted T crown plates. The diagram gives the sides and ends as 6" high but at some time the sides were increased in height and it became part of the HR breakdown train, with added footboards and handrails. It survived a very long time as it was not scrapped until the 1950s. The following photograph was taken by JL Stevenson in 1952.
The wagon also appears in several photographs in the first volume Peter Tatlow's railway crane books. I haven't built a model yet as I haven't seen a photograph of it in original condition but I think I will have to make some assumptions and get on with it.
Type O was the apparently un-numbered breakdown crane match truck. It also appears in the photographs in the breakdown crane book. It is a very similar looking wagon to the modified 2147, with an added support for the crane boom. It was 19'6" long on the same 13' overall wheelbase. Peter Tatlow has drawn this wagon as part of the crane drawing, and uses the same drawing to illustrate both Type O in original condition and the modified Type N wagon. I haven't checked the dimensions but the photographs show that the Type O match truck had an extra hinge at the centre of the side so there appear to be two doors each side and the wagons were different lengths. So take care if you are building models of the HR breakdown train.
Type P was a six wheel tank wagon for tar only 16' long on a 11' wheelbase. From the diagram it looks like the much later post grouping six wheel milk and beer tank wagons. I think I have found it in a photograph but it is part obscured and not totally clear, I am not sure so won't show it here. It could be the Loch Ness monster hiding at Blair Atholl. I would like to build a model but can't without more information.
That just leaves the brake vans to complete this ramble through early Highland Railway goods stock. I would like to be able to say the brake vans are simple because there are only a few types in the diagram book but it would not be true. Even one I have looked into in detail and built models of has some major anomalies in the information available. Next time.