Yes, its Yōst, not Yöst. Richard was right (no surprise!). Sorry ‘bout that, my mistake.
This advert was drawn by G.C.Glover, a well-known English illustrator of the period, known mostly for his Robin Hood books for children.
The advert appeared on page two of The Connoisseur, a monthly English magazine for collectors, in November 1901.
The scan of this image is 18.2MB, so if you click on it to copy it, you will find it is much larger (more than 1MB) than it appears here, still large enough for use as a poster etc.