You are using some kind of USB enclosure or dock to "prep and test" the drive?
Is this correct?
What OS is on the MacBook's internal drive right now?
Is it 10.6.8? (that's what came on my own 2010 MacBook Pro)
I'm going to -guess- that the problem is due to changes in how Apple's latest OS's work, particularly with the new "CORE storage" systems used in Yosemite and El Capitan.
Hmmm... could there have been a firmware update for that model of MacBook?
That could be holding things up.
Just wondering -- how do you know the drive you created is "bootable" if you can't actually BOOT from it?
OK, if the installation went ok, it -should- be bootable, but the proof is in the pudding, so they say.
More thoughts:
Have you tried actually swapping out the drives yet?
The process isn't that difficult (you NEED THE RIGHT TOOLS), and will take only a few minutes.
Then try booting the SSD actually -inside- the Mac.
If it won't boot either way, then perhaps it might be a firmware update issue.
The "farthest" I've taken my own 2010 MBPro is 10.8.5 Mountain Lion. That boots and runs fine, although I still use 10.6.8 as my "main OS". it just runs cleanly and boots up in five seconds flat.