Firstly, there's Edith Reynolds. The ad below appeared in the November 1949 edition.
Here is Edith Reynolds two years later, in the November 1951 edition. After two years, she evidently had not sorted out her supply problems, which leads me to think the company was a one woman operation. Demand was obviously still high, despite the cost. These creatures were only stocked in expensive London shops.
Julip have just one advertisement in the magazines I have. The company was just seven years old when this advertisement appeared in August 1953.
These models must be among the earliest of the Julip originals. The models certainly looked quite different when the company was created in 1945. Ursula Hourihane wrote a book called The Tale of Julip, published around 1948, illustrated with photographs by Gee Denes of the current Julip models, which were completely unlike what was to come. Positively fanciful, these ones were. Scroll down this link, which shows the horses being made.