Italian bonds and low-risk don't seem to go together. Isn't Italy one of the counties in financial trouble -- along with Greece, Spain, Portugal...? A very quick Google showed bank interest as higher than bond interest; maybe Hubby is a genius.
Anyway, I would try to get some grocery ads (Xeroxes) from 5 yrs, 10 yrs, 15 yrs, 20 yrs ago. Compare prices and how they've risen. This would be a good intro to talking about inflation.
Investing in real estate is investing, and would allow him to sleep at night. Having a rental apartment is what saved Fernando Aguirre when Argentina's economy collapsed. The paper assets became basically worthless. Surviving the Economic Collapse by Fernando Aguirre
An entertaining personal finance book for beginners may be The Barefoot Investor by Scott Pape. The author is Australian, so his examples are Australian, but the message is universal.
If I read the chart correctly, Vanguard's year to date yield on its S&P 500 index is -0.79. Yes, it may improve, but we may be in a sideways market instead of a bull -- which means that after a lot of up & down volatility our money remains where it started.
Your husband may not have the sophisticated investing vocabulary you have, but his solid grasp of peasant economics may be ne plus ultra. Try and understand why he's coming from where he's coming from. Sometimes the past is prologue