As far as I know, that's from the huge amount of stuff Mike did with Adrian Baker over the years. Some of it was officially released (via several mostly covers albums), some of it has leaked out, and there's probably more we haven't heard.
And it's all really pretty weak, to put it politely. It all sounds like Adrian Baker on top of cheap synths and drums machines (which I think is precisely what it is), with Mike sometimes layering some vocals in (sometimes seemingly only a lead). If it was all considered "demos" (which some of it is seemingly *not*), then I guess at least the production values could be forgiven. But all the songs are beyond bland. It all sounds like those Hawaiian Tropic and Hyatt Regency and Sonic Drive-In advertising jingles.
But no, I don't think this is really an "SIP" outtake. While Baker is on "SIP" here and there as I recall (because he was in the touring band in the 1990-92 time frame), "SIP" was a Melcher production with mostly Love/Melcher songs. All of that Love/Baker stuff is presumably written either by Baker or by Baker and Mike.