The first half dozen paragraphs of Creek Audio's history, as described in the following link, go a long way towards explaining the unsophisticated nature of the CAS4040's design in its original guise:
https://www.creekaudio.com/history/
The company's founder, Mike Creek, had a background in the production of cut price consumer electronic goods and clearly came up with the CAS4040 in that spirit ie, the amplifier was built down to its £100 price point. It would also seem that Mr Creek, working from his spare room at home, did not at that stage have any real technical/design background.
For me the amplifier would be of some historical interest in hi-fi terms and might be worth restoring as such. However, it's not an amplifier that should be considered for serious use.
Alan