On 8/15/2009, Dave Headrick wrote:
I found it curious that all three of the top bows were welded (small weld about 3/8" - 1/2" long) to the side linkage assemblies in addition to the screws which hold the parts together. Do you know if this factory original?

Pretty sure they are all like that as original factory issue. I have never seen one that was not welded in the same manner, all the same welding pattern nice and neat. As a career machine design engineer I can tell you for sure that the screws alone will not hold it secure for long. There are no dowel pins or square corners for the parts to lock together, so there would be constant stress on the screws every time the frame is moved, raised or lowered. If you made the screws very tight and used thread lock adhesive they might stay put. Otherwise the screws would eventually work loose from relative motion between the parts.

My first impression was that the factory folks only figured that out after the parts were in production with screws only, then began welding the parts after assembly. This would have happened very early in production. If that was true there would be no need for the screws, just use some punched holes and alignment pins for fixturing prior to welding. Perhaps after the fact they figured it was just as easy to use the screws for fixturing prior to welding rather than changing the design to eliminate the screws and then having to build a welding fixture. You never know. Fifty-five years ago when labor was cheaper they might have figured it was cheaper to screw each one together rather than building a welding fixture.