In the tables below, I have tried to establish when models were first introduced - either by the manufacturing company Minitrix or by the UK vendors Hornby Minitrix.  Hornby started selling the Minitrix products sometime in 1973.  Before then, Minitrix had already started to produce a few UK outline models.
Information has been gleaned from the few Minitrix and Hornby Minitrix catalogues that I have been able to locate.  When a model is first introduced, it seems that the version which is put into print, is sometimes at odds with the model that is eventually manufactured.

In this first section, there are a number of models which appear in the pre-Hornby catalogues.  The warship models are printed with different names from the ones that eventually became the standard.  Models with other name sometime crop up from this period.  The Blue Class 47 shown in the UK 1970 catalogue didn't make it to the Hornby line-up for another 10 years !  The Britannia model shown in the catalogue appears to be a picture of the Trix OO model.  This list is organised in order of when the models appear in the various pre-Hornby Minitrix Catalogues - at least the ones to which I have access. 

When Hornby started marketing the models in 1973, they did so with a collection of 4 - N201 Dock Tank, N202 2MT with Tender, N203 Britannia, N204 Class 27.  By the end of the year, the price lists show that N205 the 2MT 2-6-2 loco and N206 the Blue Warship had been introduced.  Interestingly, the price lists never reveal the name of either warship, and at some point a maroon version seems to have been in production. 

The list below is in order of when the models first appeared in the Hornby Minitrix Catalogue - indicated by the fact that new models were indicated as such on the photos.  There are places where I have had to take an educated guess, as my references are incomplete, but price lists and the dates on the Technical data sheets have helped.  Where there is room for doubt, I have placed a question mark alongside the Hornby date.

One item of note is the re-designed N203 Britannia which was modified to sit on the same chassis as the Mallard, and acquired a slightly different number of 51-2037-10.  This number appears on the Technical data sheets, but rarely on the boxes.
Another slight variation is the Green 2MT with Tender N213.  There are some models around which have the cab number 46402, rather than the more common 46406. and Minitrix allocated the number 51-2038-50 to this variation (from the 1985/86 catalogue).

Early in 1987, the problems with the UK currency exchange rate amongst other things, forced Hornby to pull out of dealing with the N gauge models.  Many continued to be manufactured and/or marketed by the manufacturing company in Germany - Minitrix, and now appeared in the green and yellow boxes - many of which were now plastic - and carrying the Minitrix 5-digit number rather that the Hornby numbering system.  Thus the Green 2MT was no longer N213, but 12038.

Four models, shown below, were never marketed by Hornby, but the plans for their production were well underway when Hornby ceased their association with Minitrix.  The two Flying Scotsmen had been designed to fit on the Mallard chassis, and the two class 47s were variations on the County of Norfolk and the Queen Mother, which had proved to be popular - and merely required a new clip on body shell.

The Minitrix Catalogue for 1988 is interesting in that it lists both varieties of the Flying Scotsman as brand new models for 1988, and shows a picture of an un-named, un-numbered grey-bodied 4-6-2 loco which otherwise looks like the finished Scotsman - but clearly not yet in a form that was available for photographs for the 1988 catalogue.  A shop price list of the time shows this as selling for £83.79.  The same catalogue lists all 8 UK Minitrix diesel locomotives as having limited availability.  I am guessing that these were no longer in production and supplies were limited to the remaining stock.   The Mallard is not listed in the catalogue or on the price list in 1988, but the Nigel Gresley is.

Last edited 26 Oct 2020