Mortgage originations by thrifts dropped 8.2 percent from the end of 2004 into the first quarter of this year, according to data from the Office of Thrift Supervision. OTS-regulated institutions disbursed $141.49 billion of home mortgages during the first quarter, the industry’s lowest quarterly volume since the first three months of last year. Originations of refinance mortgages actually held up a little better, posting a 5.6 percent decline from the previous period. …