Grenade ID Please

[Weasel]

I was sent these pictures of a grenade to ID, not my area of interest so i would appriciate one of our experts helping me out with this one please, All empty and inert was full of mud when found in a back garden in the 1970's near the river Tay.
Best regards Weasel.

 

[Millsman]

WW1 Mills No 5 or No 23 Mk I or Mk II. If it has an aluminium filler screw it would be an early No 5.

 

[Weasel]

Thank you very mch for your reply Milsman, i thought the curve on the base was distinctive but did not which model it was.
Best Weasel.