Ultimately I stuck with my plan to do the US space rockets in order and put Redstone-Mercury (much more interesting) aside to complete the second, rocket TV-4, called Vanguard, which put the US Vanguard satellite into space on March 17, 1958. While the Vanguard satellite was by far the smallest and lightest of the early satellites, and only the fourth artificial satellite (and second US one) to orbit earth, it was the first solar powered one, operating for seven years rather than a few weeks, and is today, by far, the oldest artificial satellite still in orbit.
I have no enthusiasm for the rocket itself, which was a terrible, anemic little launch vehicle made from sounding rockets pushed, really, beyond their limit. It failed on eight out of it eleven satellite attempts, usually spectacularly (which made if fun to tune and watch, at least). But the model is done now, and it looks good on its carrier car. The model is 1:48 scratch-built, made of poplar dowels turned, grain-filled, primed and sanded, painted, etc. You will see below that I have yet to need to use one of the big eight-axle rocket transport cars I bought.
It's not nearly as big as the Jupiter C-Explorer ahead of it, but it is a sleek, long thing.
Even with just two rockets, this US Space rocket train is already fairly cool looking. This morning it is being pulled by two LC+ GP7s just because they happened to be on the layout already, but they looked really good doing so and fit the time-period, too, so . . .
Below is the next in the series, Redstone-Mercury, not too far from completion. It is a bashed Glencoe Jupiter C kit with scratch-built capsule and escape rocket tower, etc. I will mount it on its transporter car with the tower unattached and off to the side. Even so, it will be about 21 inches long (Vanguard and Jupiter C are both about 19") so I made need to use one of the big rocket transport cars, but it would be nice if I cam save them for Atlas, Thor-Agenda, titan-Gemini, etc.