Not impossible at all. However Webleys experimented with several different coated finishes during the early/mid 1970s to save the expense of bluing and particularly polishing beforehand. They carried on making blued pistols alongside coated pistols and the former became the F Series according to Tom Cooper from notes I took after one of our conversations.
The Premier certainly makes for a fascinating study as there are so many different models.
Kind regards,
John