I bought them in Maplin years ago.
That is really fair enough since you purchased it years ago, only recent production had labels on the pins
There are several models of the Arduino UNO board. Some of them have the labels on the header pins and others just have these labels printed on the board, but there is no difference on how they work and their functional features.
To know how to distinguish a counterfeit Arduino UNO you don't need those labels, you can take a look at the following link to see some examples and peculiarities of these ones:
I got this message from Arduino Store email support
This is just awful, I can't believe I bought the official product under false pretenses :(
It's pretty much known to the community that the official boards (the latest production) have labels on the header pins. This is just unfair, and the saddest part is I can't do anything about it. I have an inferior product and I paid the same amount of money since others who ordered from the official store got their Arduinos with labels printed on the header pins. Even an official reseller at Aliexpress guaranteed me if I had ordered from them I'd have a board with labels on the header pins and on the board, why can't the Official Store do this as well?
I have two counterfeits (ATMega328P boards using Arduino logo) and these don't have labels on the header pins. While tinkering with these counterfeits, it become apparent to me that I often plug the jumper cable on the wrong header pin, because it's really not quite easy to determine what pin I am plugging the cable, I've decided to order one from the Official Store thinking that it would have labels on the header pins and to my dismay when it arrived after 1 month of waiting, there were no labels to be found.
I was very disappointed and sad by this fact I thought I paid a premium for quality control and it turns out not all boards are produced equally, some have labels printed, some don't. It's cost cutting that trades off user experience. It's really disheartening for my part as I expected that it would be one of the prime features of a Genuine board that would set it aside from counterfeits, even if not explicitly mentioned in the Counterfeit page; no other derivative or counterfeit boards have labels printed on the header pins.
All I feel now is regret, full of regret for paying $22 + $13 shipping for an inferior product. :( :'(