Mike the flower stalk (peduncle) in Lavendula pedunculata are 10 -25cm long while those of L. Stoechas are 1-5cm so looks like this plant is Stoechas unless my visual measurement is amiss.
Michael, I assume you mean mm. I said maybe L. pedunculata going by what is sold in garden centres. I would be happy calling it L. stoechas cultivar. Most of what is spreading could be an older variety with small top bracts.