Arlingtonians for a Better County unanimously endorsed Richard (Dick) A. Buffum and Al Eisenberg last night for the two Arlington County Board seats to be filled in this fall's election.

Since county Democrats don't meet until May 16, Buffum and Eisenberg left open the question of whether they would seek the party's nomination or endorsement.

More than 200 people attended the convention of the ABC, a self-described nonpartisan group with a tradition of endorsing Democrats who run as independents for the County Board. Many members of the ABC are federal employes who are barred by the Hatch Act from participating in party politics.

Buffum, 56, a retired CIA foreign affairs analyst, told the group he would prefer "to unleash the enthusiasm of the Hatched people and go for the endorsement" of Democrats. Eisenberg, 36, director of government affairs for the American Institute of Architects, indicated he would prefer to run as a Democratic nominee.

The five-member County Board currently has three Democrat-backed members and two Republican-backed members, Walter L. Frankland Jr. and Dorothy T. Grotos, whose terms expire this year.

Frankland is seeking reelection and Grotos has said she will run for county treasurer.

In their speeches last night, Eisenberg and Buffum said that if elected they would emphasize controlled development, housing issues, responsible fiscal policies, quality schools and the problems facing the elderly.

Eisenberg said county Republicans confuse "tenure with experience" and "prefer to campaign on the notion that they have a right to representation on the board as Republicans, rather than on the issue of whether they offer the right representation as public servants."