Thank you for sharing this.  I have had my extra class license for many years.  Despite having collected several HF radios, I mus confess that I have never operated on HF.  Only 6M, 2M, and 70cm FM.

But back to radios.  My first HF rig is an Icom 735, which I believe is similar vintage to your Kenwood.  Your show got me thinking, and it turns out my radio also has a battery, which I hope and pray is not leaking all over the radio.  Now I have another project!

Thank you for sharing!