The Cypriot military received a dubious windfall today -- a motley collection of 21 Land Rovers, jeeps and vans from the Palestine Liberation Organization.

The unloading of the vehicles, some of which had to be pushed, concluded the latest saga in the Israeli-forced evacuation of the PLO from Beirut.

The Israeli government held up the departure from Beirut of about 1,100 Palestinian guerrillas headed for Tunisia yesterday because they had loaded the vehicles on the vessel, the Sol Phryne.

After a day of confusion, including the blockade of the harbor by Israeli gunboats and comments on the delay by Secretary of State George P. Shultz and Secretary of Defense Caspar W. Weinberger, the ferry finally was allowed to leave with a U.S. guarantee to Israel that the vehicles would be removed before the guerrillas reached Tunisia.

Thus, the Sol Phryne made an unscheduled three-hour stop at this southern Cypriot port to unload the vehicles. The guerrillas then sailed on to Tunis, two days away.

Weinberger had called the episode a "little glitch" and even that seemed an overstatement when the Cypriot National Guard drove -- and in three instances pushed -- the vehicles onto the quayside.

Except for camouflage netting on one, none had any military equipment. They came in a variety of colors -- canary yellow, military green, powder blue and fire-engine red -- and could easily have been a lineup of stolen cars.

Several were fairly well battered. One had a flat tire.

Their importance was strictly symbolic -- for the Palestinians to show they could take the vehicles with them, and for the Israelis to prevent the PLO from having them. The solution was a standoff.

When the dispute arose yesterday, U.S. Ambassador Raymond Ewing approached Cypriot Foreign Minister Nicos Rolandis to assist. Rolandis said the government was willing to be helpful, and he worked out the agreement to bring the vehicles here with Farouk Kaddoumi, the PLO foreign policy representative who had arrived here yesterday to greet the first PLO evacuees who stopped here en route to Jordan and Iraq.

The guerrillas, who crammed the stern of the ferry today to wave and chant victory slogans to a crowd of about 100 Cypriots and tourists, did not seem disheartened as they watched the vehicles being unloaded.