Possible unmarked Spectacle larva?

Possible unmarked Spectacle larva?

Observation - Possible unmarked Spectacle larva? - UK and Ireland. Description: 30mm larva found on a wooden shed in September. Deciduous woods and undergrowth all around, I'd need to check the undergrowth species but a lot of hawthorn tight to the rear of the shed. It has the shape of a Spectacle or Dark Spectacle but not the white

30mm larva found on a wooden shed in September. Deciduous woods and undergrowth all around, I'd need to check the undergrowth species but a lot of hawthorn tight to the rear of the shed. It has the shape of a Spectacle or Dark Spectacle but not the white markings. D.Spectacle larval stage probably better (July to Sept) as Spectacle only has a 2nd generation in southern Britain(UKmoths), further north a single gen. (May-mid July). From the north of Ireland so the location is possibly more typical of N.England, S.Scotland.

Any help much appreciated? Is there a larva the same shape as a Spectacle without the white markings?