Digital BW, The Print

All of my digital B&W work up to now has been done using images
straight from a digital camera where the starting colour space is
known.  I've been able to get WYSIWYG results by turning the image to
monochrome in PSCS2, and printing through Qimage to QTR using one of
the designated QTR gray spaces for Qimage.

Now I am working with an image that I scanned from a B&W 35mm negative
on my Epson Perfection 1650 Photo using Vuescan.  I'm not getting
WYSIWYG results at all.  The prints come out quite a lot darker across
the tonal range.

Some of the testing that I have done leads me to conclude that I have
assumed the wrong profile / grayspace.  I have tried outputting the
image from Vuescan as both a single channel grayspace image, and a
three channel monochrome sRGB image.  I was sure that the sRGB image
would give me wysiwyg results, but not so.

What space should I be assuming that the output image from Vuescan is
in?  My best guess based on testing is GG2.2 

F_P

(Yes, my screen is calibrated using a Monaco Optix XR Pro.)