Well, after trying to determine the additional working distance that I will need with my 100mm macro lens, it looks as though such a distance will be considerable. So I think I might opt for degrub's suggestion of buying a used Nikon Micro-Nikkor 55mm manual lens with a Canon camera body adapter. According to the instruction sheet provided with the ES-1 slide copying adapter, I might also need to add a PK-13 extension ring between the camera body & the lens to get the 1:1 ratio.
If anyone has any thoughts on this, I would appreciate hearing from you. Thank you.
Kit