Window architrave - help me reinstate to previous

[rarara]

Our bay window has a set of hideous curtains which we want to remove and use blinds. Here is how it looks with the curtains removed....

At some point in time a 10" strip of board has been added to the top which the curtain rail is attached to, but judging by the old wallpaper that's underneath, its a recent addition. My questions is.....

If I remove the piece of board what should be at the top?? Presumably there used to be something a bit more decorative, particularly at the top of the wooden end column of the window frame? Some form of surround or architrave?

For instance, here is what is at the bottom:

Can anyone suggest or show me a picture of what I should be trying to get hold of to reinstate the original top part to the bay window??

 

[foxhole]

Any neighbour have similar you could take a look at.?

 

[rarara]

Unfortunately not

 

[rarara]

I managed to see a neighbours and they have what seems to be the same part as in the earlier skirting picture, but reversed. So this bit with the blue line around in this orientation:

This tops the wooden column - any idea what this part is called??? And where to get one?

 

[Deleted member 174758]

Turned and bisected moulding. You'll need to find a wood turner and get one made. Can't see such an unusual item being an off the shelf part

 

[rarara]

Turned and bisected moulding. You'll need to find a wood turner and get one made. Can't see such an unususl item being an off the shelf part

 

[Dave54]

As JobandKnock says, stuff like this is made by turning. It's made in halves (generally) glued together with paper between and "split turned" With a piece like this that has to be the right angle to fit in, it would at least give a flat side to work from for cutting the angle. I'd probably do that part on the bandsaw.
Local woodturning club might have someone willing to do it for you.