Salamander Archetype: Can they be "bridged" together?

You are most welcome.
Yes Grainger would likely have yielded more choice but I am not known for patience and once my mind is made up to do something I want it done yesterday... lol.
One big advantage of home brewed is that you can design it to be any way , shape or form to suit you. Within reason of course.
Good luck with the project.
Have fun and stay safe!

Thanks Steve.
If I remember correctly the all thread rods are 36" long and 5/8" diameter.
Mine are stainless which cost a lot more than the plain galvanized but look a lot nicer and the nuts screw up and down on them a lot smoother than they did on the galvanized.
Yep I was playing with these rods and nuts in Home Depot quite a while before I decided which and what to buy.
5/8"  was thickest they had in stock and looking at it maybe 3/4" would have been even better.
However my rack is sturdy enough and as you can see I left room at the bottom for the amp which sits on another home made little stand.
Perfect?
Heck no.
Cost effective?
Hell yes.

OP
This is exactly what I did, built my own.
Not quite next to nothing but one heck o f a lot less than Salamander.

Home Depot supplied the stainless all thread for the rods and all the nuts and washers.
Amazon supplied 4 butcher blocks in Maple.
Drilled all the way through on three of them at corners and the fourth just drilled in approx 1 inch as this would be top shelf.

I love it!
Instantly adjustable shelves in a heartbeat for change of equipment.
Levels in seconds .
It's child's play to build it IMHO.

Check my system picture to see my rack.

Good luck.