Yes, your explanation is essentially correct.

• Dravya Pariksha (Dravyaparīkṣā) by Thakkur Pheru is indeed a very important work for Indian numismatics.
• It deals with:

- Types of coins current in his time - Their weight, metal content, measures, and exchange value - Practical methods of testing and refining metals (especially gold and silver)

• Thakkur Pheru was a Jain scholar who served in the royal treasury/mint, and he also wrote important works on:

- Metallurgy (e.g. Dhatutpatti) - Architecture (Vastusara) - Mathematics (Ganitsar / Ganitasārakaumudī) - Astrology (Jyotishsara) - Gemology (Ratna Pariksha / Rayaṇaparikkhā)

So, describing Dravya Pariksha as “a crucial work on Indian numismatics giving details of weights, measures and values of contemporary currencies, and noting that Thakkur Pheru also wrote on metallurgy, architecture, mathematics, astrology and gemology” is accurate.