Graham, IF the issue you are referring to is the Dec2020/Jan2021 edition, Vol.70 No 842, then by an unbelievable coincidence I have a spare one of those.
If I remember correctly there were distribution challenges with this issue and mine was so late I decided to buy one off the shelf. Not surprisingly, it then arrived! If this is the edition you are short of and you want it simply send me your details in a PM and I will send you my spare. It is still in it's plastic bag!