I also have the following wiring and miscellaneous parts:
-JC-130 Y-junction (2x, one is 450/350/50, another is 250/350/50), each $40 shipped;
-SM-BTC1; external battery cage (mounted between frame and bottle cage using extra long bolts), with built-in external B-junction, $45 shipped

Items sold:

-Ultegra R8050 Di2 shifters, very good condition. Two very minor cosmetic blemishes (one on each shifter, see fourth and fifth photos). This is the version that has the hood-top buttons. $190 shipped OBO. These are for rim brake or cable-actuated disc brakes.
-Ultegra 6870 Di2 front and rear derailleurs. Both in very good conditions. The RD has seen maybe 200 outdoor miles and was used primarily indoor. The cosmetic blemishes are not on the viewing side and are obscured in use. $100 shipped for FD and $145 shipped for RD. Get both for $230 shipped OBO. Please note that the mounting screw on the FD is after-market and should work with braze-on.
-SM-BTR2 Di2 internal battery. Holds charge well. $70 shipped CONUS OBO.

Video showing the shifters, derailleurs, and internal battery in working order [URL="https://1drv.ms/...rTDfzKSehDg?e=Lfh3UR"]here[/url].

The entire set (all four parts listed below) is available for $475 shipped OBO.
Shifting minigroup has been sold

-2-button climbing switch (SW-R600), $40 shipped. Sold.