Semi-Factory Engine Kits available for leasing

Frick that’s cool.

Correct me if I am wrong, but were these purchasable about 10+ years ago through the power parts catalog? This would be enticing for privateers in the 250 class. 

Interest from privateers is obviously depending on what the power output of this package is. 
I mean i dont think there are 250 yamaha riders in exm/mx2 who ride with the GYTR package since the power output isnt that attractive (compared to the cost).
 

I believe so. They would also do factory rebuilds of a stock motor (not sure if they still do).

Yes, back in the day they were called "sxs" or "factory" kits. Like the one below, you optionally had some other parts available, like a larger water pump, clutch components and some bling stuff, at additional costs. 

Up until 2009/2010 they had also a fully kitted out bike from factory called sxs-f, which was super limited in quantities, offered to racers through select dealers. Those already had the full engine package installed, a full Akrapovic exhaust, different triple clamps, updated suspension (black lugs and lowers on the forks, high speed/low speed compression and rebound adjustments on the forks and shock), different hubs/rims, as well as the factory "brown" brembo brakes. That thing cost almost double the price of a standard SXF at the time. A buddy of mine had an "08, it had some ridiculous service intervals (and parts for the engine were available only on request directly from Austria, but your dealer had to send the old/worn parts back to KTM).

Later on factory editions became a thing, but they weren't going nuts with the engine packages on those like before.