I have the model with the bracket that attaches to the frame with 4
long bolts, with another bolt for the steering bracket. I now have
considerable "slop" in my steering even with the steering nut
tightened so much that I can hardly move the handlebars back and
forth. It has so much give that I am actually afraid to ride the bike
because it feels like I do not have control of the steering. Does
anyone have a diagram or exploded view of what the steering
bolt/nut/washers - the whole assembly should be composed of, from the
bolt head through all the parts to the nut?

Another option I might have is to replace this whole assembly with an
upgraded assembly I recall being discussed on the old Topica blogs -
is that still available anywhere?

Thanks,

Dan