I was able to get it resolved. Thanks much for your suggestions.
The challenge I had was A. my father was in the hospital (Bumrungrad). B. the hospital’s biz department at first said they could arrange a medical visa, but then later said they needed to have my father’s bank book with the requisite money in it since he was on a ret. visa. – this was odd, as I expected Bumrungrad to be more knowledgeable. C. my father’s bank book was in Samui and did not have the requisite funds. D. my father’s visa expired on August 4, thus I had 2 weeks at the time, and there was a long holiday.
Manareet (Pattaya) wanted the bank book. And was not sure about the letter from the hospital. However, they do seem like a good option for those who previously used Key Visa, i.e. they can handle a no-funds ret. visa, and other visas.
Thai Visa Centre (BKK), although higher in price, made it pretty easy. They said they only needed a copy of the bank book regardless of funds, plus the passport and a couple digital photos. They picked up and delivered the passport, with the 1 year ret. visa. Renewal, and it took 8 days, even though immigration was closed for 5 of those days. 18k THBx total.
I was able to get someone to copy the bank book (which is still on Samui) and send me pdf’s, which I printed out. I had medevac’d my father from Samui to BKK / Bumrungrad, and did not bring much with us at the time on the jet.