I'm looking for either a kit, or a conversion, that allows me to backdate the Academy M3A1 to the earlier cersion.

Specifically, I need the octagonal welded turret with the extended sides that form the commanders cupola. Three pistol ports (right- left, rear) and AA machine gun mount on left-rear.

Any ideas?

Verlinden used to make one.

https://www.scalemates.com/kits/204126-verlinden-productions-723-m3-stuart-honey-turret

Why not just buy the Academy M3 Honey kit?
http://www.kitreview.com/reviews/m3reviewcs_1.htm

I second Gerald's comment-- it has all the features you want and is an M3 already. Even comes with US or U.K. Markings in the box.
VR, Russ

Indeed, this kit is readily available It suffers from the same problems as the other Academy Stuart kits, plus one more, the interior provided is for an M3A1 and not an M3.

Paul

Yes, that's true, but it's not that difficult to eliminate the turret basket and build a drive shaft housing from the front to the rear of the fighting compartment for a true M3. Eduard also makes an update set for it. There are not many alternatives for a true M3 out there except for this kit, with the slab armor turret. For those who are wondering, the M3 used a radial engine, which caused the drive shaft to the transmission to ride high in the fighting compartment, and the M3A1 used Cadillac engines under a sub turret floor.
VR, Russ
VR, Russ

Formations also makes a lower hull tub allowing you to use the AFV Club M3 suspension bits with it. I also saw that Tiger Models does a new detailed idler bogie now too, if you want to go full throttle with the aftermarket goodies...

Damon.

As I recollect, there was a bit more to it than that, in that the ammo stowage was different too. Mind you, the M3 stowage is easier to build than that of the M3A1, as it's basically boxes.

The M3 interior was a lot more different than the M3A1 than just the drive shaft.

As Rob says, there were the ammo boxes as a start.
Plus the seats, instrument panel and the transmission were totally different.

In addition, the M3A1 and the M3 used the same Continental radial, It was the much different M5A1 that used the two Cadillac engines in the revised rear deck. AFV Club makes an excellent kit of that.

I agree that the Academy kit is the only early slab sided M3 around (in styrene) but the kit is so full errors as to make building it a significant disappointment.

The M3A1 kit is fundamentally no better except the interior is proper for an M3A1. The real problem with that kit is that it is actually a very late M3 and not an M3A1. It has riveted superstructure and the faceted rear hull overhang making it an M3 (which should then have the non-existent M3 interior). The M3A1 used a slightly different version of that cupola-less turret with a curved rear overhang plate and a welded superstructure (plus a bunch of other small changes).

One thing to note is that the lower and upper hull parts are modified copies of the Tamiya kit parts. You can even interchange them if you like. The most significant problem with this is that the turret ring of the Tamiya kit is about 1/8" (~.110") too small. This means that the new Academy turrets are the right diameters, but sit on noticeably too small turret rings which are actually placed a bit too far forward. The only correction for this is to cut out the turret ring and replace it with one the right size, squishing it in between the front of the superstructure and the engine air inlet, replacing the turret bearing mounts in the process.

All in all both kits are not great. With work, replacing Academy parts with selected AFV-Club parts and some hacking and slashing you can _get_ to a nice M3 and nice M3A1 using these kits, but you sure as heck don't get one out of the box. Either box.

Paul