Bessa I front standard adjustment?

Anyone have experience tilted front standards on the Bessa I?
My camera is fine otherwise, and the standard clicks firmly into place when the camera is opened, but the top of the lens tilts back toward the body of the camera, so it's not parallel with the film plane.
The rivets are not loose, I don't see evidence of damage, and I've cleaned pretty thoroughly, so I'm not sure what's keeping it from reaching the full vertical position. It's not really off by that much - just enough that I'm sure it will affect the image.
Thanks,
Nathan

What are you using as a reference plane? The open door is not necessarily perpendicular to the film plane I wouldn't trust it. A ruler across the open back may be more reliable, this might allow comparison of distances between the standard and the film plane, if the top and bottom measurements don't match there may be a problem.

Most of these cameras operate at small apertures like f5.6 and smaller and the depth of focus at the film plane may not be so critical as it is on cameras that operate at f2.

When the bellows is in place it exerts some slight force against the standard, if there is "give" in the standard then the alignment with bellows in place may be different from without bellows.

1. your camera's bed is not 90° to the body. Hinge bent, bed brace guides incorrectly positioned or similar is the cause. Use a tri square to check the bed's position.
2. from other pictures on the web the lens standard is held by the rivets either side of the shutter. The lens mount is rotated reward at the top. Grip the standard firmly and rotate it back to parallel with the film plane. It may seem tight but gripping the top and pulling outward while pushing inward on the bottom should get it to rotate back into position.
It may be made to rotate on those rivets for closing and opening and just be stuck.