Paul,
Good to see you here!
The rEvoDream I bought from you in 2010 still works fine!
Regarding your 15mm UW Nikkor: In the book «The Nikonos Handbook» by Jim Church, there is detailed instructions on how to diassemble the lens. The challenge may be to loosen the small grub screws on the aperture and focus knobs. These may be frozen due to corrosion between the aluminium knobs and the stainless steel grub screws. There has been suggested to use a soldering iron to gently heat the knob. Aluminium have a high thermal expansion factor, and this may help loosening the grub screws.