I explain you better. I entered in Thailand beginning of last february with a Non-O visa ( 90 days ) . About 80 days later I married. After marriage I asked for a year Marriage Visa and Immigration accepted all necessary documents and gave me a visa ( you are right, it is not an extension of Non- Visa, )up to day 2 June because my 90 days where near to expire and I had to wait for Immigration to come in my house, to check and it could take some time. But after about 10 days Immigration telephoned me and asked to go in their offices and with a witness. We went and everything was OK . I was told to go back on 2 june to get my Marriage Visa and to go before 10 july for the 90 days report . In my opinion the 400k , like you said, need to be there only 60 days before application.