This is a sequel to the thread: http://www.ausphotography.net.au/for...newpost&t=3164
The DIY reversing ring has been fabricated and now replaces the "bluetack and rubberband" workaround.
Image 1 (not the best of shots, just adequate) shows the completed ring on the right and the discarded half of the EOS body cap on the left (with evidence of the drill holes on the perimeter). The UV filter can be seen at the bottom of the ring and as can the residue of the glue at the back.
For those without proper workshop facilities (like me), the most effective way of removing the centre portion of the tough body cap is to use a hand-drill with a small diameter drill to perforate the required perimeter and finish off with a Stanley knife.
A glue that effectively bonds the body cap plastic to the metal UV filter is Vise Supergrip Polyurethane Glue (from Bunnings), with a 24-hour curing time. I used my versatile lab retort stand to clamp the ring during this curing time.
Perfectionists could of course paint the residual glue black after carefully sanding it back. So far using the ring as is has not produced any visible artifacts on the macro outcomes.
Image 2 shows the reversing ring in use. The connection of the reversed to the EOS body is secure, testament to the toughness of the body cap material (and the strength of the glue).
To protect the sensitive exposed back- , it is covered by its cap between shooting intervals.