Sounds like a fun project! Presumably you have a source for the original broadcast version already but just in case, the French DVD released in 2005 has it, complete with credits at the end of part 1 and recap at the start of part 2: https://www.duneinfo.com/giedi_prime/dune-french-dvd/
Thanks! I actually found an equivalent source in a Korean DVD I acquired last month, the only thing I have to figure out now is where the commercial breaks were placed, since neither of those have them.