The hard work is done for you. Somebody is always looking for cheap stuff for projects. Box it up and sell/put up for bids on eBay. Examples:
https://www.ebay.com/sch/i.html?_nkw=team+associated+xp120&_sacat=0&LH_Complete=1&LH_Sold=1
In my mind, the only electronics that would be of value, on a lot of today's RTRs, is the motor. The last great RTR that I remember was
Duratrax Evader ST Pro. It came with an actual Futaba radio, Orion motor, Pro-Line tires, hard coated aluminum shocks, blah, blah, blah. Sure, there are some RTR speed controls that are better than others, but the typical ones that lack adjustability... don't plan to get much for them if reselling. The latest Reedy SC600-BL2 speed controls are more on track for
the price a person would pay for them separately. Getting a Hobbywing Quicrun WP 1060 G2 is
cheaper. Just look at chop shops across the web for pricing practices.
As far as stock arms go, I'm the type of person who would rather have an arm snap than have a more flexible composite plastic piece yankin' on hinge pins/chassis. It all depends on the RC platform and its known strengths/weaknesses and surface being ran on. I'm pretty sure Team Associated did a running change on the MT10/Pro4 SC10 arm's plastic. I don't "send" my RCs to the moon and back. I'd buy the stock arms off you, if I had a MT10... things didn't work out

. Thanks for reminding me of Associated's "must buy all four" arms deal.