I got several calls from this number, the man on the other end said he was offering some "Home"improvements" I told them I didn't need any and to please stop calling me. He was then very rude. I hang up.

You are absolutely correct. No conventional phone number begins with a "1" because that signals the switch that you are calling outside your AC or in some cases outside your LATA. "1" and "0" & "00" are reserved for Direct Distance Dialing and Attendant/International service respectively.

Calls, leaves no message.

Not getting calls from HRG but many many calls from people trying to call them back. HRG has spoofed my 408 number!!! Made report to FCC but still getting calls. Hope these A-h0!35 are stopped!

Received a call from "HRG Construction" stating they were a "veteran construction company", and were offering to provide a quote "while they were in Palo Alto".
The only HRG Construction that comes up on the internet is in India.  There's no HRG-anything listed at the Contractors State Licensing Board (cslb.ca.gov)