According to Media Factory's Pokemon Card Official Guide Book 2000, this card was a prize for Shogakukan's Illustration Artist Contest.
However, no one actually knows how many cards were given out, and as time passes, rumors were going around.
For years it has been questioned by collectors around the world, until recently an answer was found.
As mentioned above, the Illustration Artist Contest. This contest was held 3 times in total, by Monthly KoroKoro Comic Magazine, a magazine for Pokemon related informations.
A small number of winners were selected each time. The best illustration might be used for the card design, and there are similar contest going around.
The first Pokemon Card was sold on 20th October 1996. This means the winners were announced after that.
Tracking back the date, this will be the timeline the contest was held.
1st time : November 1997 (No.235)
2nd time : May 1998 (No.242)
3rd time : June 1998 (No.243)
And this will be the timeline the winners were announced.
Among the winners from the 1st and 2nd time, 4 illustrations were actually used as the card designs.
1st time : January 1998 (No.237)
2nd time : July 1998 (No.244)
3rd time : August 1998 (No.245)
The chosen illustration cards are printed on the magazines.
Total winners are
1st time : 3 Top Award Winner + 20 Winner = 23
2nd time : 1 Top Award Winner + 7 Winner = 8
3rd time : 0 Top Award Winner + 8 Winner = 8
In conclusions, there are total of 39 winners, which means there should be 39 cards given out.
It is reconfirmed that this card is not just a prize, like lottery prize where there are XX winners, and sometimes, more prize were produced than given out. More than 10 years passed, like any other Old Card Back No.1,2,3 Trainer cards, there are no replacement for it. Wonder when will the next time this card will appear in the market.