These nouns have come into the English language because they were the informal noun related to the object concerned.
What must be remembered is that an auctioneer and other catalogue describers use the term Penny Farthing because this is three characters shorter than Ordinary Bicycle. All describers have a limited space in which to describe the item on offer.
Also, I put this use of the informal terms down to auction houses that have sprung up over the last few years, who tend to employ describers who do not have the knowledge of a wide range of objects, whereas most of the knowledgeable ones have already been snapped up by the established companies.
Another factor is the increase of auction houses and the decrease of antique dealers. It was these dealers who had to have a wide knowledge of all antiques. If one went in and asked about the Penny Farthing in the window the dealer would come back and with the term ‘oh, you mean the Ordinary Bicycle’.
This recalls the time when we had to provide references that we were in the trade before one could participate in the bidding at the auction. Since this rule has been relaxed, so has the terminology of the items being catalogued.
Not every auction house is as specialised as yours, so I say to Mr Card: live and let live!