Cheek bolt size on record 52 1/2 vice?

[Deadeye]

I've acquired an old vice, a Record 52 1/2
It's missing the bolts that hold wooden inserts onto the cheeks, and the holes are too small for my thread gauge.
Anyone have this vice and could tell me the diameter and tpi please?

 

[AndyT]

5/16 inch, Whitworth. Usually available on eBay in small quantities.

 

[porker]

Whereabout in Bucks are you? I have a bag of countersunk bolts that fit. You are welcome to a few if you want. I am just south of Aylesbury.

 

[Deadeye]

Thanks all - porker, I'll pm you