The search engine for Numismatic Literature permits you to search by key words. 246 articles, most relevant to the topic of ancient imitations, and most with enough detail in the abstract to let you know if the article would address your particular area of interest. The Circus , etc. Unfortunately, the search engine for Numismatic Literature of the American Numismatic Society does not seem to permit you to find abstracts it has merely by knowing the volume and abstract number. Roman Coins from North West England by David Shotter, Lancaster Univ., 1990.
Suggestions are very welcome.