[john70t]

(from a brief search):
Parts and diagrams: https://www.matoemparts.com/#Parts_By_Category

Quieting tweaks: https://airpsi.com/low-noise/how-to-quiet-an-air-compressor-6-noise-reduction-tips

60db 2.5gal 2.4cfm https://airpsi.com/low-noise/rolair-jc10-plus-trim-finishing-super-quiet-air-compressor/

68db 8gal 2.4cfm https://www.campbellhausfeld.com/air-compressor-8-gallon-horizontal-quiet-dc080500.html

73db 20gal 4cfm https://www.homedepot.com/p/Husky-20-Gal-Vertical-Electric-Powered-Silent-Air-Compressor-3332013/311273546?MERCH=REC-_-pip_alternatives-_-300085154-_-311273546-_-N&