Edward I Newcastle Pennies, relative scarcity of Class 10?

[Coinery]

Does anyone have any insight into the relative scarcity of the three Newcastle classes, measured against themselves? 
 

Over the last 3 or 4 years I’ve managed to pick up a class 3 and a class 9 in good grades, but have struggled to find the class 10 in a similarly collectable grade, with the attached coin, bearing the full Edward legend, the best I’ve found to-date.

Edited 20 hours ago by Coinery

[Coinery]

The class 3 and 9 coins available in much better grades generally.

 

Edited 21 hours ago by Coinery

[TomGoodheart]

I have no idea, but it occurs to me that perhaps this is the sort of information that Martin Allen at the EMC might have to hand?
Mra25@cam.ac.uk

[Coinery]

Many thanks TG I’ll message him. ☺️

I’ve been trying to glean a bit more information from the SCBI 39 about the closure date of the Newcastle mint, and of the date signatures of class 10, to see if I can work out how long the Newcastle mint operated into that class. The date of the mint closure appears to be September 1302 but, depending on who you listen to, the commencement of Class 10 is either September that same year (Fox brothers), or nearly 18 months earlier if you go with North?

The Fox brothers’ date would suggest a minuscule mintage of class 10 coins under Newcastle, whereas North’s dates would allow a production window of 18 months. Given the number of Newcastle Class 10 coins available, it makes me wonder who’s got the commencement of the class right?

I’d love to acquire every mint in every class someday! 
I’m currently this far down the rabbit hole, so fingers crossed:

 

Class VI Bury St Edmunds (#1)  

Class VI Bury St Edmunds (#2)  

1c London  

1d London 

1d London (1 x reversed N on reverse)

2a London

2b Canterbury

3b London

3c Canterbury 

3e Newcastle

3e York

3g London

3g Lincoln

3g Durham

3g Bristol  (1)

3g Bristol  (2)

4c Canterbury eBay

4c London  

4d London 

6a1 London 

7a London

8a London  

8c London 

9b1 Durham 

9b1 Exeter 

9b1 London 

9b1 Newcastle  

9b2 York (Royal)  

10ab London 

10ab Newcastle  

10cf1 London  

10cf2 Durham

10cf2a London  

10cf3 London

10cf5 London

12a Canterbury  

12a Canterbury 

12a Canterbury

12a London 

14 Canterbury  

14 Bury St Edmunds 

15c Bury St Edmunds eBay