Reliquary for a soft heart - trying things out

This is what my mind came up with in response to the question -
how can I make the meaning clearer and keep it medieval?

I found out some Latin sayings that seemed relevant,
and tried out scripts copied from
Faces of Power and Piety  by Erik Inglis 2008 J Paul Getty Trust,
a book that I found at the British Library

And now I've finally decided what I'm making, I thought I'd better get on with it.

This was my attempt to make the lattice from my image.

The red crosses could be something else, but I haven't thought what yet. I think red looks good when it's like this, but when its around a red heart it might look wrong. In my picture it started off with halo spikes, so perhaps I should think about that possibility.

I also need to think about how I'm going to attach the ribbons with latin on them. And if it will work to have them in the grooves like that.

I also wondered about making the squares stiff, by fixing the ribbons to wire at the back or something.
And whether they should start out in squares, or whether it might be better if their size is graduated across the shape of the heart.

Lambs heart from Instructables.com

from nosetotailathome.com

Obviously if I am going to make a soft toy in the shape of a heart I have to do my best to make it look realistic. It will be covered a bit by the golden reliquary, but what's visible has to look as though it was intended to look like the real thing (only soft and not rotting!). And I didn't particularly want to have a real one in my house. So I found a clear photo of a lamb's heart on the internet, and painted it with acrylics. That didn't quite give the texture, especially of the arteries and fatty parts, so I drew over it in colour pencil.

Painting of a lambs heart

The textures of the different parts are very different from each other. The large vessels at the top are smoothly rubbery, but not shiny - like octopus parts. The red muscle is often more purple than bright red, and fibrous, and shiny in places. And the fatty parts are much bigger than I would have predicted, are lumpy in parts, and smoother in others, and split by brighter red blood vessels. The fat seems to be thickest, and smoothest, in between the lumps of heart muscle.

Thinking about the colours and the textures here, I picked out some fabrics which I thought might work to represent these tissues. I found myself picking velvet, linen and cotton, all familiar from my research on the Medieval period, but I also wanted silk and chiffon because of the subtle shine to them. I picked one polyester netting fabric because it had something of the same texture as the more knobbly parts of the fat around the heart. I also picked raw sheeps wool that I had picked up from thistles next to a sheep field recently, because it has a similar colour, and I wondered if I could make it a similar texture to the fat pads.