Initial attempts making these of solid and drilling retrospectively were inconsistent--I managed one real beauty--but failed to repeat it neatly... I found some large diameter pierced girder in the WEM Koenig PE set.

By cutting lightly angled sections of this PE strip with holes I was able to make the bases this PE, sealing the open angled edges with stretched sprue and mounting the finished deal on a sliver of styrene to gain the correct height.

The photo below explains the method; it was fiddly work on very small components.

Being an avid and addicted PE buyer--I guessed I would have something suitable...-- 
The WEM Borodino PE set contains these leg mounts--alas in a five legged variant- Pentapod mounts -- and the base ring etched integrally...! Close enough to give the viewer the feeling they are looking at the real thing....

Because the base of the resin cast fighting top is ticker than the steel plate of the real thing, I had to shorten the etched legs a little, so  to ensure the gun would be the right height in relation to the splinter shield wall; this is thankfully not really noticeable when the guns are placed. (Future YS kits will hopefully have a PE fold-up fighting top with a thin metal floor.

A is the PE mounting from the WEM set

B is the barrel==> cut down from NNT 1/700 5.9 in German barrels...

==> I reasoned that 1/700 5.9 in ( divided by two!) was close enough to a 1/350 3" QF gun barrel.

C is some Modelrailway thick etched ladderstock-from, which the hinge bracket supports were cut

Some small bits of wire, PE shoulder braces along with a heft portion of patience completed a fair rendition of these guns. The folded Heptapod was given a small drop of white glue to give a bearing surface for securing the barrels to, thereafter construction was reasonably straightforward.

The kit resin items were alas a bit clunky for my liking. The pedestals are sanded cocktail stick points infused with CA--taller and thinner!

I made the framework of thin copper wire, carefully and tediously measuring each length individually and then tacked in place with matt varnish. This allowed final positioning and was afterwards reinforced with a droplet of CA applied via a flexible piece of stretched sprue. 

The QF gun apertures were bridged with a piece of stretched sprue so as to permit the next stage, the spanning of the framework with thinned white glue to represent the canvas. I thinned the glue 50/50 with distilled water and applied using a long thin watercolour artists ‘ rigger’ brush, this having very long and soft hairs can maintain a large span of white glue film without applying any pressure that might distort the fine framework...

To ensure the platform floors stayed within acceptable levels of ' thin-ness'... I added the rails around the OUTSIDE edge of the floors, using superthin over-etched WEM items.

I decided to use them. However in fear of thin resin rods attemptiong to distort with age a bit of modification would be required. I carefully drilled all the way though from their bases using a pinvice and inserted thick stainless steel wire rod to guarantee their stability indefinitely.

The yards had only slight taper according to photos—I used some thin brass tubing. The centres of which were built up with paint layers. They then had a thin stainless steel wire inserted through them and stabilise into a laminate with glue dribbled in, this would prevent the yards distorting when the halyards were tensioned.
 

The white waterline stripe was surprisingly tricky--as the white line is at the very top of the armour belt, and due to the varying degrees of tumblehome from fwd to aft the lines had to be eyeballed to get a consistent line that withstood inspection from all angles. The white line on this model is a decal; made by using the excellent products of TL decals, a German firm whose products I have used before available here. 

These decals are made using a screen printing process--and as such have no visible carrier film beyond the print-making them ideal for my purposes.

The sea-scape was deliberately made in a lightish blue hue—emulating the sandy bottom with patches of rock and week giving the light and dark shades. Water was quite flat—offshore breeze (as verified in photos) The vast ensign on its very tall ensign staff was again copied from period postcards of the ship.

The fwd hawse-pipe was opened, the casting surround made of brass wire and had a cover made of brass.
The resin anchors of very distinctive shape were cleaned up, lightly shaped and installed.

Two coats of white glue were applied, once the lower edge has been cut and painted it gave a fair rendition of this feature...

The no.8 was based on a contemporary Marius Bar photo of the ship in 1899.

a) flat.

b) too fat....

c) too short for most applications...

d) tricky to apply to take any kind of rigging loading...

This is mainly due to the stanchions on the real ship being mounted OUTBOARD-- with two standoffs to give presumably a greater athwartships  spread of canvas-along with  less trip hazards.
The aforementioned issue of not having spaced or drilled them prior to embarking the finer detailing was solved by NOT attempting to drill,  but instead use a  sharp pushpin.
 

The lower crank of the stanchion fitted neatly into the push-pin created hole and was secured reliably by adding droplets of CA to level. Once set firmly-- The upper brackets were partially done with a drop of white glue or stretched sprue where access was difficult, especially in amongst the forest of boatcranes...(!!) The aft enormously tall ensign staff was installed along and the awning bracing structure was made.