Oh man I love this thread!
The AX10 is the real OG. Crawling wouldn't be as popular as it is today without it. You should absolutely pick that up for 100 bucks and send it!
The pros:
You'll notice how simple it is compared to the majority of modern crawlers. Makes it easier to learn. Easier to work on. It's a transmission bolted between two U-shaped twin vertical plates with some axles 3-linked to the skid. If you wanted to modify it and change things up once you become more comfortable with it, it's the perfect platform for crawler creativity and building what you want.
You can get the manual for the truck
right here and see the exploded views with part numbers.
The majority of the important parts are still in use today, albeit with different part numbers. I'll explain more on that later.
What will break, if it hasn't already been upgraded?
AX30392: The stock diff bevel gears are pot metal. I would go out on a limb and assume, if the truck has been driven as a crawler (it looks like it has) at least the front gears have already been replaced with hardened options. It's worth asking the current owner if they know what gears are in the axles. But, it is not a deal breaker, because you can still get these replacement gears. These same pot-metal gears were used in the RR10 Bombers, SMT10, Wraith, and Yetis. Lots of aftermarket (and probably still some pot metal) still readily available.
AX30421: These break on today's rigs...not so much on the AX10. This part is still readily available at places like Amainhobbies,
here.
The skid plate is the only "unique" part on this truck that would be hard to find a direct replacement for. But a custom skid plate is one of the easier crawler mods you can do, especially on a chassis like the AX10's. It also won't break unless you throw the truck off a 10-story cliff...so you don't really need to worry about it.
Driveshafts: You can tell the rear shaft has already broken and been replaced with the green aluminum one. Driveshafts are super universal and easy to replace. Even if you can only find a replacement that is too long, you can easily cut them to length.
The cons:
1. You'll notice it's not realistically scale like 99% of the modern options. The AX10 was considered a "comp crawler" back in the day before everything went scale and performance was exchanged for looks. That thing will crawl straight up a wall! If you ultimately want something that looks like a real truck, the AX10 may not be the best platform.
2. None of your crawler buddies will appreciate it when you hit lines with your 20-year-old "hunk of junk" that their modern rigs can't even perceive.