The following details can be found on the Malvern Industrial Engineers website - http://www.miac.org.uk/
"Mckenzie & Holland equipment was used in many British and overseas signalboxes including one at Hartlebury and were exhibitors at the Worcestershire Exhibition in 1882.
The premises built by the Worcester Engine Works Co Ltd went through a number of different occupiers before being purchased by Heenan & Froude Ltd in 1903.
Mckenzie & Holland merged with other signal manufacturers in 1901 and became a limited company at the same time, wholly owned by the Consolidated Signal Company Limited. The Worcester operation was closed in 1921. The Mckenzie & Holland locomotive was then purchased by Heenan & Froude Ltd who took over responsibility for rail traffic.
The Vulcan Iron Works was occupied by Avery Stephens & Co, ironfounders from 1921 until 1936 when it was sold to Heenan Froude. The site has now been re-developed and no evidence can be found of the Vulcan Iron Works".