там много всего есть, в том числе и обьяснение странного экспозамера:
The R-D1’s light meter does not use a traditional centre-weighted pattern but instead has a sensitivity bias towards the lower left, like the Voigtländer Bessa R2/R3/R4 cameras.

и сенсор у нас не как в д50, а как в д100:
The sensor in the Epson R-D1 is an interline-transfer CCD (Sony ICX413AQ), as used in the Pentax *ist D, Nikon D100, Starlight Express SXV-M25 and other cameras, first manufactured in 2002 (Figure 1). The sensor in the Nikon D70 and D50 is not the same as the D100 CCD, as sometimes suggested on the web: although the D70 CCD is a newer design, its advantages lie in faster image acquisition rather than improved image quality.
ну и еще много всего включая рамки под 90мм, отключение кнопки блокировки диска, сборку-разборку и т.п. ;)