None of the Stirlings on Mapping Sculpture fit here.

This might be painted plaster.

Yes, not bronze - but not plaster either. It's zinc/spelter, or possibly aluminium, painted brown to look vaguely bronze-like. I agree with the reading of the signature as 'F [or P] STIRLING', but have no idea who that might be.

This is presumably by a Scottish sculptor and probably second half of the XX century. A 1945 portrait of Shinwell shows him looking younger and with less advanced baldness:

https://artuk.org/discover/artworks/emmanuel-shinwell-18841986-206686/view_as/grid/search/keyword:shinwell/page/1

How do you know it is Manny Shinwell? Does it say on it somewhere? Cos I am old enough to remember seeing him on TV , and I have looked at some online piccies to remind me, and it is either a bad likeness by the sculptor ,or it's someone else.

We have no record of what, if anything, is on the base.

When adding this discussion I was prepared to accept that it depicts Manny Shinwell, if a poor likeness: the ears are the wrong shape and size; the nose has a definite bump that Lord Shinwell's never had; and he had a significant amount of hair on the top/back of his head even in advanced old age. This sculpture shows hair that has receded completely to just above the ear level at the back. I thought the eyes and mouth were more characteristic.

This photo was taken in 1984, on the occasion of Lord Shinwell's 100th birthday.
https://bit.ly/3d8Qm7U

Lord Shinwell, aged 90
https://bit.ly/37AmyzK

It is a rather crude rendering, but the identity of the sitter is open to some doubt. The collection should be asked about provenance or other evidence that this is, in fact, Shinwell (or rather, about the basis for the identification).

Comparing image #5 with the 1974 photo linked by Marion does not give a very good match. Apart from the hair, the nose is different.

If the bust is not of Manny Shinwell then there possibly is no connection between the sitter and Scotland, which opens up the possibilities of the sculptor being from anywhere in the British Isles.

Does the accession number signify that date of its entering the collection in 1989?

If someone could rub some coloured chalk dust or the like into the scratched signature, I think it might reveal a little more ????

I suppose this could be an amateur effort meant to be only a very rough approximation of Shinwell.

I've asked the collection to look at the inscription when the building re-opens.