From your text, you seem have things a bit 'Bass-Akwords'... You don't [add] shims to a neck pocket to lower it, you need to either shave the bottom ot the Heal's neck or rout out the pocket a bit to lower the neck. Yes, from your pictures, those 'Barrels' are setting a little high for my...
I just might have what you've been looking for... Take a look!
Custom 60's style Tele with 4-position switch that throws both P/u's into series with 100% boosted output. Interested, look at 'Reverb.com'
Well, if you want to change a 'U' shape neck to a 'V' shape, just get busy with a 'Draw Knife' and a 'Wood Vise' and you can re-shape your own neck to your satisfaction.
You can't really screw it up, unless you scrape too much away from the sides. Give it a try, go slow and carefully, you'll be...
A very quick check, just to see if the two middle terminals on the switch, that puts out the signal to the volume potential, has a 'Jumper' connecting the two together... IF you don't have that jumper in the middle of the switch, you probably have a switch issue and need a new one.
I'll offer three more:
Eat a Peach, Allman Brothers
Late for the Sky, Jackson Browne
And one that probably you've never heard of;
Gypsy Queen, Gypsy Band
Have a listen to this great original Minnesota 1970's group, who wrote all their own...
Oh, boy, did you really open up the 'Archives'... Here's my first guitar, ever.
That little 'Axe' opened a world of music and pop culture for me and millions of others too.
Actually, my 'Silverstone' was a white body with black pickguard and a hard case with a small 8-watt amplifier installed...
Me Too, SAD! I could give forty songs better than the four listed here, and I'd get a whole lot of support... "Personal opinions are exactly what their worth, zilch"
Even trying to list the 'Top 4' is simply exposing their ignorance...