I am happy to take a look. However, new to this field, would you please describe what is the current problem with current riecoin code? What do you expect to be done by "merging Bitcoin Core 0.16.0" and how would that address Poloniex's request? Should we first take a look at current riecoin code, apply fixes in Bitcoin Core 0.16.0, or reversely, replace the POW in Bitcoin Core 0.16.0 so it can talk to Riecoin network?
I'm time short so can't do this myself but may be able to give some pointers. What's your technical level in terms of development (none, some, already looked at Bitcoin source, etc.) and in terms of the process of merging/managing source code in Git?