Is it possible to use parts from different iPhone6 models?

I have a working iPhone 6 with an iCloud account lock that I purchased at a deal on craigslist thinking I could simply wipe and reinstall the OS. As well all know, this cannot easily be done.

I am now looking for an iPhone with a cracked screen or some other damage that I can use the main logic board from the damaged phone and the screen/case/button, etc from the working one.

My question is, how close to the original working model do I need to be to be able to exchange parts without too much trouble? The working model is an "a1549".

I have my eye on a 6s listed on ebay for a reasonable price that looks like its been thru the reamer - however it still boots. Would like to use all parts from my working phone and only use the logic board or main internal components of the broken display one to achieve one working phone. Is this possible?

Thanks.