Try to put together a "stand-alone" no-dependency gem for rlp (recursive length prefix).
Try to use the "best" of
- https://github.com/cryptape/ruby-rlp (is standalone but now archived - and may support too much) and
- https://github.com/q9f/eth.rb (- see /rlp - is simpler but "inline" and not standalone)
Check the issue with the source encoding - ASCII-8BIT required (for BINARY string encodings for constants) - why? why not?