As recommended above, I finally connected with Matt Aikawa. He works for the The New Audible Difference in Palo Alto, CA. It is strange his name is listed as the Jeff Rowland Retailer and the name The New Audible Difference is not listed. I asked him about the possibility of a new Jeff Rowland Integrated amplifier using the Class A/B design similar to the Model 625. He said he would check with Jeff Rowland and let me know. Most likely, he said, a new integrated could be 6+ months away (and maybe more).
I am still disappointed that the Jeff Rowland Deign Group never responded to my three email messages. In any case, I now have the name of someone who represents the JRDG and will keep me posted about any new Integrated amplifier. Thanks.