The APE(X)C series included the following machines:
* APE(X)C: Birkbeck College, London, first time operated in May 1952, ready for use at the end of 1953
* APE(N)C: Board of Mathematical Machines, Oslo (N likely stands for Norway), also known as NUSSE
* APE(H)C: British Tabulating Machine Company (It is unclear what H stands for - perhaps Hollerith as the company sold Hollerith Unit record equipment
* APE(R)C: British Rayon Research Association (R stands for Rayon), ready for use in June 1952
* UCC: University College, London (circa January 1956)
* MAC or MAGIC (Magnetic Automatic Calculator): "built by Wharf Engineering Laboratories" (February 1955)
* The HEC (Hollerith Electronic Computer), built by the British Tabulating Machine Company (later to become International Computers and Tabulators (ICT), then International Computers Limited (ICL)), a commercial machine sold in several models and later known as the ICT200 series.  There were likely the derivatives HEC 1, HEC 2, HEC 2M - M for marketable denoting the machine's orientation toward commercial rather than scientific customers, and HEC 4 (before 1955)
Only one of each of these machines was built, with the exception of HEC (and possibly MAC) which were commercial machines produced in quite large numbers for the time, around 150. They were similar in design, with various small differences, mostly in I/O equipment.  The APEHC was a punched card machine while the  APEXC, APERC and APENC were teletypers (keyboard and printer, plus paper tape reader and puncher).  Also, the UCC had 8k words of storage, instead of 1k word for other machines, and the MAC used germanium diodes in replacement of many valves.