Wiston's 15th c font

After the porch I had a look around the rest of Wiston church; but being a new graffiti hunter I wasn't sure about some of the bits of potential graffiti. The church has been altered and had whole new extensions such as the Apse added. So I decided to err on the side of caution and focussed on something was covered in graffiti and identified as coming from the fifteenth century  - the font.
What did Brigit find almost straightaway? A pentagram! On the font!
This isn't a bored parishioner scratching away during a tedious sermon of indeterminate length.
I don't know very much about the medieval church's rites and ritual, but I'm pretty sure the congregation didn't  just hang around the font for fun during the service. I reckon parishoners  could find a quieter corner to practice stone scratching skills. Someone very purposefully put this here, and much more besides.
The font is absolutely covered in graffiti. In this photo I like the way you can see the subsequent layers of coating painted over the original stonework, and I suspect that whatever was applied to the stone obscures more graffiti underneath.

Around the font there are angels carrying shields.
Everyone of the shields is scored with graffiti.
Sometimes even the faces are marked, this one with a cross on its forehead.

I keep seeing these long score marks too, not to mention grids.
I wish I knew what they meant.
 I know this photo is a little blurred. My fancy camera is lovely, but technically too complicated for me at the moment. To my great shame I couldn't get decent shots when I took it off the auto function. So I reverted to using the camera on my phone. Anyway, what I was trying to capture is the compass circle partially scored across the shield. 
More parallel scratches
Bits of graffiti partially covered.
I wonder why the stone font was painted with this substance? 
The "M" mark was too deeply etched to be obscured though.

Another altered shield

 I'm not sure if this one is graffiti or not?
None of the other rim crenellations have it as a decoration.
Another scored and scarred angel

More long scratches 

 and still more noisy graffiti emerging.


Finally - here are the last three shields

Finding this has really made me want to find out more about the font and who was involved in its creation. I shall return and get better pictures another day (also using a scale to take the pictures against). Tomorrow I am going to Nayland. I wonder what I will find at St James's?