Hello Larry,
After reading your post, I went out to my car and grabbed my Tachihara 5x7 field camera. I have used it a great deal and I have not had the problems you describe. But, the shortest lens I have used on it was 150mm. Mine is a standard design.
I can get the film plane to with in 4 3/4 inches of the lens plane by moving the back of the camera as far forward as it will go. At that point, the smaller tightening knobs then hit the large knobs that move the front of the camera back and forth. The swings on the front still work at this setting as the swing plate goes under the wood on the back of the camera.
By taking the lens support out of the verticl rail at the bottom, just like if you were going to fold down the camera, and leaning the verticle uprights back--using front tilt-- I was able to move the lens board to about 1 3/4 inches of the ground glass. I tightened the lensboard in place with the two round flat screws at the top of the front verticle supports. The front focus mechanism worked fine even when the ground glass and and lens board were that close together. At its closest setting, the bellows is scunched together (a nice technical term) and prevents the front from going back any farther.
I tossed on my 90 mm lens, a Schneider Super Angulon XL-100*, and it focused fine at infinity.
Hope this helps.
Allen Friday