[COLOR="DarkRed"]Welcome !
That's a hecka "wish list"...but more power to ya'...you can do it...I think...with patience.
Here's my opinion:
The Black/Gold Duco is seen far less than the Blue/Gold. Add this to the fact that Ducos, in general, aren't seen too often nowadays, and those that are are usually in questionable condition (peeling/chipped/alligatored/etc.)
You have 2/3 of the Kent already, that's pretty good...so all you really need is a FT type shell.....
Now, Kents are not very sought-after, really. They have their fans, and they have their mojo. But Kent was never shooting for the high-end of the market back in the day. There is a fair amt. of info on the company online. Do a search for "Kent Drums, Kenmore, NY".
Slingys, on the other hand, have tons of fans. But even given this, people don't go as nutz over them as say, Rogers, Gretsch, Ludwig...although they are certainly as good a quality. I think this is because Slingerland took such a dramatic nosedive in the '70's that the name was foever tarnished. Thanks in part to the internet, the pre-nosedive ones are now getting their due...and folks are now learning that back in the day, for a hecka long time, Slingerland was THE leading name in drumsets.
All of this is to say, arguably, Slingys are superior drums than Kents.
Like I said.....if you are hoping to nab matching Duco finishes on eBay or C'list or such...you ill need to be very patient...because the Black/Gold is just a rarer color scheme. If you have some serious $, you can always contact online vintage drum shops and see what they have. But, seriously, their prices are 2x to 4x the price of second-hand market value. Just the way it is.
Duco finishes, being painted, were...back in the day...the cheaper finish alternative to wrapped finishes (pearls, sparkles, glitters). The sound is the same. The drum construction is the same. It was just a matter of lower pricetag and lower costs of producing a painted finish than a wrapped one.
The other alternative is to actually just get a vintage shell, and have it painted Duco. Motorcycle or Auto detail shops can do this and match the colors spot-on....and really, the prices aren't that bad to do such a thing.
Whew...hope this helps some....[/COLOR]