I recently acquired a 7 knob Allwave 23 chassis and amplifier and will go through it for winter project. It came with a wood panel and all the escutcheons. So far, I have dusted it off and looked it over for obvious issues. When I took the front panel off was surprised to see 3 holes on the front, one large and 2 small. It soon became apparent these holes were the mounting configuration for the beat oscillator button on the 5 knob model. This set has the micrometer dial, so perhaps was sent back to Scott for an upgrade or maybe someone had another set and did the upgrade themselves. There is nothing suspicious looking about the wiring to the phono switch or the beat oscillator button. If someone added these controls they did a very good job, and it was done long ago. The serial number of this set is K-650, how would that number fit in the time frame? Also worth noting, about half the capacitors are Potter and the rest are Sprague, a few appear to have been changed but most appear to be original. There was a discussion in another thread here about Potter capacitors and it was generally agreed they were only used in the early models. It appears that this is an upgraded 5 knob set, which does not matter much. Has anyone seen a 5 knob set upgraded like this? It seems unlikely that it came from the factory this way. The set seems relatively unmolested and should clean up well so will be a fun project.