I am working on a graphic which displays simplified 3D models of all Mars exploration spacecraft to date.

This will give you the idea: http://i.imgur.com/e4amxAD.png

But I've run into a problem; the fifth spacecraft launched at Mars was "Mars 2MV-3 No.1 aka "Sputnik 24" which was apparently a lander (represented by an ERROR in the graphic). I cannot find any documentation concerning the type or appearance of the lander, or whether it flew with a flyby bus similar to the 2MV-4 probes.

If anyone has any idea what sort of lander this was (I expect something like the Venera 4 entry probe) or whether the flyby bus was present/similar to some other probe, the help would be appreciated. I find there is a saddening lack of information regarding this first landing attempt.

I have never seen any picture of this spacecraft (and I don't think any exist). on the other hand, it was probably a Zond-3-like bus (with hemispherical radiators, unlike Venera 4) with a Venera 2 or Venera 4-like lander on top

Boris Chertok’s Rockets & People, Vol II: Creating a Rocket Industry , NASA SP-2006-4110 provides a vague description:

Each of the 2MV spacecraft consisted of two compartments. A standardised orbital compartment contained communications and control equipment that was identical for Mars and Venus. A special compartment housed science equipment determined by the wishes of planetologists. In some cases, instead of a special compartment, equipment intended to land on the planet was installed as part of the descent vehicles, which of course, differed for Venus and Mars. Spacecraft designed for landings were given the code numbers 2MV-1 and 2MV-3, while those designed to conduct research on the planets while flying past them were dubbed 2MV-2 and 2MV-4. The “fly-by” spacecraft had photo-television units installed on them.

There's also a photo of 2MV-4, so it seems they have the same bus only the lower bit in the stand being possibly different. Click to view attachment

Thank you both! I will post here again once the graphic is complete.