I don't think so, but I believe the 2016 data should give you a decent enough idea. I doubt much has changed between 2016 to 2017 in terms of estimating your chances.
Just at a glance (2016), it looks like non-US IMGs who got a Step 1 between 241-250, 23 matched but 12 did not match, while for Step 2CK between 231-240 15 matched but 14 did not match. I might be wrong, but I believe radiology tends to slightly favor Step 1 over Step 2, though it might depend on the program. Your research might help a tiny bit. Observerships might help only at the places where you did your observership and if they produced good LORs or connections.
Your big negatives are that you've already graduated 3 years ago, so hopefully you'll have a good explanation, and hopefully you've been doing something clinical during that time as well. The other big negative is of course your status as an IMG, assuming you need a visa sponsorship, but nothing you can do about that. Some programs simply won't sponsor a visa, so don't bother with those.
Otherwise, for you, there's no harm in applying (other than to your wallet), especially if you have a backup plan to do radiology in another country.
Good luck!
