Interesting. I have not tried it and i will presume you are going to use current blockdata for each of those installs. My guess would be: It depends on when those coins ended up in the wallet. Pre split coins would be good in booth versions but past split coins are only good on the chain they belong to. I am not sure if the node would adjust your balance on startup and subtract the "bad" coins but i am very sure you wont have any luck transfering them.

In a scenario where you would switch block data between versions it depends on what caused the split. If the recent event caused the switch your node would at least be able to communicate with nodes of the version the block data originally belonged to. If the version changes that triggered in 2.0.1 caused the switch (or are at least another factor) your node is likely to get stuck instantly because blocks from it's own version don't match the chain and blocks from the other version don't match the protocol so there is nothing to communicate with. There might be a chance of 1.3.1 not being oh so picky about the protocol though. Again past split coins would only be good on the chain they belong to. On the other chain those coins don't belong to you or were even never mined.

Anyways, this is pure theory and guesswork. Just saying i would not have much hope for it to work very well (or rather at all).

Edit: Regarding the split due protocol changes in 2.0.1. Aside from the relevant code parts discussed earlier you can also check the original poll held by conan. There is 2 options. 1: "No, don't update. 1.3.1 forever." and 2: "Yes, update. Will require softfork". I think the discussed code parts changing the protocol is what he ment with softfork.

Edit2: Regarding price recovery. It's really hard to estimate what happened to the likely ill gained coins that presumably fueled the big dumps that triggered the decline but my guess would be around 25% of it is spent by now. Since it is impossible to predict the thoughts of the owner that does not have to instantly mean we will see more dumps but it's a possibility. Point still stands, we need to get the network updated to fixed builds or this uncertainity is multiplied by infinite which is bad(tm).