Introduction and Question

[cloudwalking]

Hi, my name is Robin and I live in Sydney Australia. I have a modified lidgard 25 trailer sailer. It is modified by having a less inclined stem and a half sloped transom giving her about 10 more inches of waterline length. She is a strip western red cedar hull with epoxy glass sheath inside and out. Inside the finish is clear epoxy so all the timberwork is on display. The hull is 2-pack painted ply. She was well built and is in good condition for a 20 year old boat.
Whilst doing a bit of maintenance to the keel case I noticed that the keel was holding water. A small packer had fallen off the keel case and this led to the keel not going down in the correct position which in turn led to some damage in the rear part of the keel where I suspect the water got in. There is some localised rot there which I am not overly cocerned about, easily removed and treated.
The keel is a steel frame with a lead and steel base. This has been shaped over with ply made from douglas fir with a maple exterior. All timber was coated at the time of construction with a west system epoxy sealer. The ply was them glassed over with epoxy and chopped strand glass under and woven mat over.
Apart from the area where the water got in the ply is in good condition but everything is damp including the outer ply veneers it seems. The ply is not delaminating at all that I can see. However, the steel frame has started to rust.
I have cut a couple of 50x100mm holes in the top of the keel and a couple of 30mm holes just above the steel base and all the rusty sludge has been washed out.
This is where the complications start.
I considered flooding the inside of the keel with anti-freeze. As you can understand, getting access to ALL the insides without pulling the whole keel apart is tricky. I discarded this idea as there is always the risk that the anti-freeze makes the rust worse once the rust inhibitors wear off. In reality, treating the steel is more important than the ply. The steel is structural, the ply isn't and seems to be hanging in there ok. After much discussion with a good friend we then decided to treat the steel with a water based rust converter. This would then be rinsed off and once dry to try and spray as much as I can with CPES. Assuming I don't get complete coverage I was then going to apply either tectyl506 or penetrol, haven't decided which yet.
The holes at the bottom would be semi-permanently sealed and the ones at the top which get wet but are above the waterline, would have removable covers to allow me to monitor things and allow the insides to breathe when the boat is not in use.
So after a long introduction, my questions are.
Firstly, am I on the right track?
Are there any conflicts between tectyl or penetrol and epoxies?
Are there any conflicts between rust converters and epoxies?

By the way, love the site.