FOR PHASE II of the McLean Gardens redevelopment plan, which began in May, 3,800 "invitations" were mailed to prospective buyers of 360 renovated apartments in existing buildings.

All except about a dozen famil-size units (starting at $112,000) of the 210 units offered in Phase II have been sold. Tenants should begin moving in next month, according to marketing and sales director Donald Epner.

"We had an overwhelming response (about 6,000) from people who first wrote in to request invitations to inspect the models," says Epner. "We could have used five times as many one-bedroom flats as we had. Some of those people were moved over into Phase II."

The original commitment to people who wrote in for invitations, says Epner, has been honored. The model rooms are now open to the public seven days a week.

Prices at this point range from $80,000 for a one-bedroom flat to $130,500 to $157,500 for a four-bedroom duplex. (All of the studio flats and studio lofts have been sold.)

Phase III of the McLean Gardens Limited Partnership will involve renovation of the 150 cooperative apartments, and Phase IV, construction of 630 condominiums. Target date for completion of the entire complex (of 1,350 units) is 1983.

When McLean Gardens first opened in 1943, a Washington Post story said, "More than 6,000 applicants are doomed to disappointment."

It could be the same story today -- only in greater numbers.