In the past, it would have been a selection of second hand tank engines and second hand coaches.
Now it could be decided that at some point the whole network was updated, the restrictive tunnel at Ryde Esplanade cleared and standard modern rolling stock replaced the ancient Tube trains. Either Siemens Desiro trains or Bombadier Turbostars run from the pier head to Shanklin.
But would that be identifiable as the Isle of Wight?
Only if the rest of the layout was a true and accurate model of the line. And it would be nearly indistinguishable from any other modern railway.
In the March 2011 edition of Model Rail, there is an article by Richard Foster positing the survival of Ventnor station into the electrified era (it is claimed that the line was cut back to Shanklin because the section to Ventnor would have required an additional substation). The track layout is derived from the 1939 plan published in Southern Rails on the Isle of Wight Volume 2, by Ian Drummond.
Ventnor is one of the most easily identifiable former stations, like a model railway the trains ran out of a tunnel mouth into the station, making an accurate scenic break.
So what would Ventnor look like if it had survived?
Well one of the key changes at the former station site is the large water tank near the tunnel mouth. Though this feature may be associated with the water pipes currently occupying the railway tunnel that would make it so expensive to reopen, they are also an identifiable part of the current location. The rest of the station site is occupied by various industrial units.
At its simplest, the line could have been reduced to a single line terminus, which would be rather boring (you could just model Shanklin if you wanted that). The Model Rail version makes a few changes to the layout but the strange moving bridge required to access the island platform remains. Iconic it might be but it is unlikely to be acceptable for the modern age.
So imagine that money was found to provide the additional substation and third rail was provided to Ventnor station. What parts of the line could survive.
Well, one platform face is an obvious requirement, but again boring. So if the platform adjacent to the station building is kept (I will call it platform 1, I have not found a reference to the platform numbering when it existed) but truncated to provide access to the former island platform (taking the Foster plan to its logical conclusion). So, the former island platform is kept, platform 2 provides additional access to the train in platform 1, so passengers can exit the train via platform 1 and enter on platform 2 or some combination of the two. Platforms 1+2 would deal with the normal electric service. Platform 3 retains its run round loop, and possibly a few sidings.
Goods services would be extremely limited on the Ryde pier head to Ventnor railway, there is no real method of getting the goods on or off the railway from the outside. The main access point for goods entering the island was Medina Quay on the Newport Cowes line. With that part of the network gone (but wait for later postings) there is no opportunity for a proper goods service so we are stuck with infrastructure trains.
So for the Ventnor station model, two or three 1938 tube trains would provide passenger service, and 03179 would provide motive power for the departmental service. The Island Line book lists the modern stock, most is available ready to run.
A track plan will follow later.