Rule #1 is - when it looks golden, there is also chance that it isn´t gold. Just saying
one dip in nitric acid will tell you if it is real gold plated.
If it is on stainless is hard to say, altough it would be very advantageous for you to have it on some relatively low reactive substrate. Then you can easily strip the gold. With that quantity, I will do a test run (to see if you are onto something). There are several possibilities - I2/KI, cyanide, sulfuric stripping cell (maybe). And many more.
Yes, you can dissolve it all in AR - that is also an option, but if I were you, I would firstly try to not dissolve the base, if it isn´t necessary
With 30kg of material, there would be ugly ammount of acids used and in turn waste generated.