As with most swordsmiths in the 16th century, I believe that Muramasa school was a workshop producing blades in small batches. The three generations always mentioned were the heads of the shop, but the actual craftsmen making the swords were more numerous.
This .pdf template has been carefully prepared from drawings and photographs of the historical blade and provided in digital format for download. Serious students of the forge can print at 100% and use it to create an accurate steel kata. This tanto can also be purchased as a precision cut steel kata.
Apprentices were asked to make as many kata as they could: these are eventually used for sword making, can be kept for a lifetime for reference and study, and their very making is a good opportunity for practice.
A good to way to learn proper sword sugata, or silhouette, is to make a kata, or pattern, from 1.25-1.5mm thick sheet of mild steel. Learn about making your own kata.