This was posted in my Master Cylinder thread, but I'll repost it here--to be more on topic.
This is a 1950 CJ3A, which I've just acquired. I first drove this Jeep in 1999, but the owner only just just decided to sell (they're going to be selling the ranch and consolidating on their much smaller island property).
A lot of it is original material (at least as far as I can tell). The most significant change has been to the steering--it's been upgraded to power steering using parts from numerous vehicles (the steering column and wheel are from a 70's vintage Camaro, I believe) and no longer resembles original Jeep equipment either above or below. I think the axles are stock. I'm pretty sure the tranny and transfer case are. (3 speed, no overdrive.) It did have locking front hubs added (not standard equipment on a CJ3A, according to the books I've read). The seats are not original (and there's a back seat), and a roll bar has been added. The engine is the old flat-head. I think it's actually a 1949 engine. The previous owners had been given the spare block when they bought it, and since the 1950 block had been rebored once before, when they rebuilt the engine, they decided to use the older block, which hadn't been. The instrument panel is not original--it has more gauges.
One old feature which I think is "neat" is the old starter (which has been rebuilt at least once, the last time c.2002), which still has the push button on the floor to engage the pinion. You could leave it sitting open with the keys in it, and there are very few people who could start it! The starter engage button is actually hidden under some secondary heater hoses than come out to a heater unit located between the front seats--this Jeep spent much of its life in Northern Alberta, and the extra heater was required!