Waiting on the final selector switch now. An original auto selector and a semi are both being center drilled. The only parts that might represent a more complete 601 other than a different lower would be a cast FSP with raised adjustment arrow and an original buffer tube, but it's been very satisfying have arrived at the point and I'm looking forward to taking to the range sometime soon. If an original cast FSB were found it would probably require custom fitting unless the taper pin holes weren't already drilled. Considering the original parts that have been found and has made this project particularly interesting and exciting..