I don't know if EBMM ever offers their wiring harnesses for sale. Like I mentioned in my earlier thread, you can buy the US L2000 harness in the G&L online store. That would make for a nice upgrade over the Indonesian harness found on the Tributes.
As far as the tuning keys are concerned, it looks like the ones available in the EBMM online store would fit but I don't know if they would be a direct fit. They would certainly be an improvement over what came on the Sterling bass. The other alternative is the aftermarket tuning key set that people installed on their Sterling earlier in this thread. I think someone used Hipshots but had to fill one of the drilled out holes for each key. I'd much prefer to use something that covered up any alterations that were need to be made but that's just me. I'll have to ask around about the stock EBMM keys as an upgrade.
As far as the tuning keys are concerned, it looks like the ones available in the EBMM online store would fit but I don't know if they would be a direct fit. They would certainly be an improvement over what came on the Sterling bass. The other alternative is the aftermarket tuning key set that people installed on their Sterling earlier in this thread. I think someone used Hipshots but had to fill one of the drilled out holes for each key. I'd much prefer to use something that covered up any alterations that were need to be made but that's just me. I'll have to ask around about the stock EBMM keys as an upgrade.