Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:5766166.
Made this remix so I could use M6 nuts and bolts (which I have in abundance) to mount the stock spool holder to the mount and use the T nuts to anchor the mount to the frame. Also added a second frame mount hole because personally, I believe in using two fasteners rather than one.
Works out well enough, the frame mount holes were a bit tight on the version I printed, It wasn't too difficult to work the bolts through them, but I made edits and reproduced the STL file for you folks.
10mm M6 nuts fit into the two slots in the back and become captured nuts for mounting the stock spool holder, pretty straightforward procedure.
Also included the f3d file because I'm a communist and I believe in the free sharing of intellectual property for all.
<3