From CQ magazine, April 1958, p59.

The SSB Q5er and its predecessor, the Novice Q5er really show the brilliance of Don Stoner W6TNS in my opinion.   Like many experienced hams he new how the narrow selectivity of the BC-453 could improve the performance of most low-end receivers,   he also knew the novice ham either didn't have one, or would be reluctant to modify it, so he designed a simple two-tube converter (three if you count the power supply rectifier) that turned it into a really good double conversion receiver that used commonly available parts for about $25.    The SSB Q5er is a very clever 3 tube converter that manages to cover all the 80-10 meter ham bands with a 2-tube product detector added for SSB.    The design evolved from 1956 to 1959 in CQ magazine articles.

In both cases,  Stoner's examples are compactly built on a small chassis that sat alongside the BC-453 which was subjected to the usual modifications, which he refers the reader to find in other articles, since they were well known at the time.  KN2DLX obviously took it to the next level and packaged everything into a neat desktop enclosure and I'd bet it worked as good as it looks.

In the mid to late '50s, surplus was still abundant and the interest in ham radio and shortwave listening was growing fast, so those projects built around cheap and available surplus were naturally very popular.

73, Bob W9RAN