Extracts of both the Symphony and the Harp Concerto can be heard on iTunes and Amazon. The former (90 seconds from each movement) are longer than the latter (30 seconds from each movement).
The extracts, as anticipated, disclose the Naxos version, certainly in sound quality, as vastly superior to the 1940 Japanese recording of the Symphony and better than the 1960s RAI recording of the Harp Concerto.
The link to Amazon UK is:
https://www.amazon.co.uk/Pizzetti-Symphony-Major-Concerto-E-Flat/dp/B06ZYBJSS3/ref=tmm_msc_swatch_0?_encoding=UTF8&qid=&sr=