A Seeburg starting from standby is supposed to scan (L to R) twice. Whether it does or not is an issue to be dealt with later. This machine is over 50 year old and rebuild-recap is way past due.
If you've dealt with the tube-Tormat era Seeburgs, you might not need a manual, but you will need caps and probably some tubes along with a basic schematics and a lube chart: