Newbie here, should I post this on any other forums here?

I would like to purchase a part outside the US, somewhere that does not use ethanol additive.

 I am currently upgrading fuel injectors
To my horror when removing the fuel bar I noticed a 1/4 inch build-up of orange corrosion on the inside bottom of the rail. The surface of the corrosion was flakey,  underneath like a rock. Its unusable.

I've seen this before in fuel systems. Where ALOT of methanol gasoline evaporates over time, as in long term storage. Not unlikely I bought this 1990 k75s with only 18,000 miles on it

Fuel bars can only be found USED these days.

If any members live or know of nations that do not degrade gasoline with ethanol I would appreciate that bit of info

Not an ideal solution but might work:

Buy a used one on Ebay from a seller with a good feedback rating who accepts returns.  If it's corroded/rusted then you can send it back at the seller's expense.

That's what I'd do.

What do you mean by "upgrading" the fuel injectors?

Up until recently, Shell in Canada sold ethanol-free 95 octane at the pump and 91 octane was only 5% ethanol.  So Canadian parts should be ok.  I've helped guys with their k-bikes and never encountered what you described.

+1 on Duck's advice. 

It is pretty unusual to have a lot of corrosion and dried fuel in the rail.  As far as a replacement almost any used rail should be okay. 

I see you are in Houston. It sounds like your bike might have been submerged in water at some point in time, possibly in a hurricane storm surge.  How does the inside of the tank look?  Have you opened it up to look at the clutch and the transmission internals?  Is there evidence of corrosion anywhere else on the bike?  What do you know of the bike's history?

Get a used rail, as has been suggested. This guy in Ohio seems to have decent selection.

Point-Seven-five wrote:It is pretty unusual to have a lot of corrosion and dried fuel in the rail.

What he said.  I've taken apart/owned lots of Ks and never seen this. Old ones usually have external paint issues but usually are OK inside.

even with 10% ethanol out here , yet to find a fuel rail - or injector filters with build up that you describe 
i wonder did the po or earlier try to seal the tank with something that got through the system somehow ? before it cured ?