Nice to hear you finally got your speakers installed gweempose! I particularly like the report on the hum. I haven't ordered mine yet, but will very soon.
Nice resolve on the auto launch problem, my Tommy of course does the same that yours did - that's a nice simple fix... Hopefully it will work on Tatmans GNR as well. Tatman I would check the online manuals for both machines and verify if the part number for the auto launch is the same, if so it would likely work. Here is a link with both manuals.
http://files.flipperspill.no/Support/Pinball/Pinball_Manuals.htm