Forking Instructions

Are there any resources available to help rewrite the code i.e. a wiki to support a fork?

no, but there is plenty of documentation in
https://github.com/zcash/zcash/tree/master/doc, https://github.com/zcash/zcash/wiki.
also check the first successful fork of zcash - https://github.com/z-classic/zclassic for further ideas

Thank you kindly, this is great!