Okay Massimo, that's exactly the clarity I'm looking for! I couldn't
really find it in the docs, but if I can use this as a more or less
official API, I'm happy. For one thing, I had overlooked the obvious
del()... ;-) A parent() function would be nice --especially since I
can't delete an element found with form.element()-- but that is really
just icing on the cake.
It means that I can now answer my own question "is there a better way
to do this":
submit_tr = form.element(_id='submit_record__row')
# get rid of the submit button and append two new INPUTs in its
submit_tr.append( INPUT( _type='button', _value=T
('<<Previous'), _onclick="location='"+URL(r=request,f='step1')+"';") )
submit_tr.append( INPUT( _type='submit', _value=T('Next>>') ) )
Looks a lot better, doesn't it? :-) This way, I can really "go to
town" on the html as generated by SQLFORM.