Kirksite die was mentioned by L.D. Miles in his 1961 book on value analysis and value engineering.
Even in 2018 it is a useful material.
References regarding Kirksite
Combining the cast kirksite tooling process with RP and CAD improves prototype, bridge-to-production and short-run parts injection molding.
Modern developments in RP techniques facilitate process streamlining-making cast kirksite tooling a superb tool for reducing time-to-market with minimal capital expenditure.