Restoring old Tesla coils

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz <twftesla-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>

Hi:

I am restoring an old Tesla coil, the one that appears in:
http://www.coe.ufrj.br/~acmq/tesla/oldtesla.html

I cleaned everything, repainted the base, polished and varnished
the primary assembly and the top terminal, and am now working
on the secondary coil. 
It is wound on a thick cardboard tube, with thick magnet wire
(~#20). The wire is intact, but has some scratches in the
insulation. It is also a bit loose over the tube (there is no
coating over it). I am trying to avoid to have to rewind the
whole coil, by moving the loose part to one end and rewinding
just the last few turns. This appears to be possible, but will
be just a little less work than to rewind everything. 
Would the scratches in the insulation be a serious problem
if I try to operate the coil? I can add a layer of varnish
over the coil, but don't want to use a thick layer, or to
let the varnish reach the original tube below.
This coil is quite strange. I don't see any sign of connection
to the lower end of it. Maybe a piece of metal foil was originally
used to make contact between the coil and the base, that has a
connector for grounding. 

I found also a very strange Tesla coil, apparently part of a
very old radio transmitter made in Germany (by G.F.D.T.). It has
a 1 turn primary, a quite small secondary coil, and a primary
capacitor split in two, one at each side of the primary. Each
capacitor is made with four test tubes mounted upside-down.
The capacitors are interconnected by an adjustable spark gap
with two balls. See the picture:
http://www.coe.ufrj.br/~acmq/tesla/gfdt1.jpg
Along with it there is a coherer receiver (look at the right side).
It is identical to this:
http://www.chss.montclair.edu/~pererat/r_0100.gif
Any information about these devices would be appreciated.

Antonio Carlos M. de Queiroz