Fatmarley
"It appears my intelligence circuits have melted"
What I certainly would change are the speakers.
I had a pair of these some quarter of a century ago. Bought them cheap from RS and couldn't sell them fast enough.
A mate had a pair, he sold them to another mate, and on both occasions they sounded slow and dull. For a long time after I assumed it was a transmission line trait until I heard some little IPL acoustics transmission lines.