In the meantime, a bit of reverse-engineering of the solution (based on photos and quick research) - fair warning: I am not a design engineer (just a computer engineer). All credit to this design goes to
@Belleville_Boater, I'm just trying to figure out the off-the-shelf parts available to make this design work. Looks like the following part inventory could work:
-Pins:
http://www.jergensinc.com/Klp-Rec-Btn-1_4x2-0-Ss_883022
+These are 1/4" diameter pins with a 2" grip length, and a double shear rating of 9200lbs [which appears to be a higher level of safety than the original design]
+Cost appears to be around $25/pin (cheaper than the replacement knobs from Yamaha!)
+Quantity needed: At least 4 (assuming we're leaving the original knobs in the pivot-point of the tower
+Note: The original design appears to have an adjustable pin (likely to account for 'slop' between the tower and it's sizing) - The pins I found don't do this, a spring and/or washer could potentially resolve this issue if there is slop in this design
-Pin Receiver Caps:
http://www.mscdirect.com/browse/tn/...uick-Release-Pin-Receiver-Caps?navid=12108876
+These caps are what the pins would connect to on ther other side of the tower from the ping
+Cost appears to be around $10/cap
+Quantity needed: match qty with pins
-Threaded Inserts:
http://www.amazon.com/dp/B002WC8T2K/ref=biss_dp_t_asn
+These are to protect the original threads in the tower
+Cost appears to be around $6/insert
+Quantity would need to match pins + threaded materials on the tower (I have to go look at my tower to see if every part of the tower connection is threaded or not).
+Notes: This variety has threadlock - may be harder to install/remove but won't have to worry about it as much (hopefully)
+The diameter of the interior threads on this should just perfectly fit the 1/4" diameter of the pins...it isn't as eloquent as a smooth-interior, but it should do the trick.
Hope this helps the group, open to comments/concerns/feedback - will post once I do this on my tower (likley in the next 4-6 weeks)