Josiah Osgood, in his Caesar's Legacy: Civil War and the Emergence of the Roman Empire, an excellent complement to Syme's The Roman
Revolution, writes about coin hoards during the time of the proscription.
These hoards have been discovered in Italy and he points out the obvious: The increased frequency of finds from the times of upheaval indicates that buried coins were not recovered because their owners most likely perished.
He cites M. Crawford (1969) "Roman Republican coin hoards."
In a table in Osgood's relevant chapter appendix the frequency of hoards is listed and shows pronounced increases in the years BC:
- 218-206 (the Second Punic War)
- 90-71 (the Social and civil wars of the 80s and early 70s)
- 50-36 (the civil wars between Pompey and Caesar, and triumvirs) with the largest number between the years 45 and 41.
As to Osgood's book, I refer again to the reviews of T.P. Wiseman (TLS) and Bryn Mawr Classical Review and excerpts in Google Books.
To quote from the Bryn Mawr Review:
"In his introduction, the author outlines a comprehensive and Herculean treatment of the period that incorporates virtually every available source: poetry, historical narratives, Cicero's epistles and speeches, biographies, coins, inscriptions, art and archaeology. He does not limit his application of the sources to Rome and Italy, but includes provincial material too."
This really means that, while both books represent the history of the era, beyond this, Syme concentrates on the ruling nobility and those "who edged them out," whereas Osgood's interest lies much more in effects of the civil war on the Italian society at large, and also touches on the provinces.
The book chapters are titled:
Introduction: missing years
1. Soldier and a statesman
2. Fights for freedom
3. Land appropriations
4. From discord to harmony
5. Struggle for survival
6. The new nobility
7. Sense of promise
8. Out of chaos consent
It's a fascinating read, and if you have the means or access to the book – and the time – I can highly recommend it.