For Britain's Lt. David Hill and Sgt. Maj. Phil Hall the Rhodesian cease-fire became reality with a sudden jolt at 3:30 p.m. yesterday. Shedding their arms, they crossed a fence separating their truce monitoring camp from the unknown, walked a few hundred yards up a small incline and nervously greeted 55 heavily armed guerrillas.

That tense beginning of a slow feeling-out process is expected to lead to the gathering, in peace, of as many as 600 guerrillas Monday in this gutted, mortared mission school about 70 miles northeast of Salisbury.

"After watching us from a distance for a long time, all of a sudden they came over the hill" in battle formation, armed with Soviet AK47 rifles and stick grenades, Lt. Hill said today.

A 20-year-old officer with the cool of a seasoned veteran, Hill is in charge of Delta 1, a rendezvous site for the Patriotic Front guerrillas in the area. They are to gather for movement to a camp near the Mozambique border.

Under a British-sponsored agreement signed nine days ago and designed to end the war between the Front and the Salisbury administration of Abel Muzorewa, the guerrillas are to be housed by Friday at 16 assembly points where they will be allowed to keep their weapons.

Even though the guerrillas were well armed, they were just as nervous as the British.

Sgt. Hall, 42, who is six months away from retirement after 22 years' service, broke the ice. One of the guerrillas asked Hall if he, too, was nervous.

"Damn right we are. There are 55 of you, all armed," he shot back, bringing an immediate burst of laughter from the guerrillas who then gingerly edged forward into the camp -- but still maintaining formation with protection on the flanks.

At that point the process that Britain's temporary colonial administration hopes will work to end seven years of bloody warfare over black-majority rule began to bear fruit.

"Everyone wanted to talk," said Lt. Hill. "They wanted to know how the cease-fire worked."

The guerrillas carefully examined the six buildings in the abandoned mission school compound and finally left saying they would come back with many more guerrillas. The expectation is that hundreds of them will turn up Monday and then be transported to the Dendera mission about 75 miles to the east where they will be housed and monitored by forces like Hill's until elections at the end of February to choose an independent government.

Hill is in command of nine British enlisted men. There is an 11th, non-British member of the team; he is the Patriotic Front liaison officer whose job is to go out in the bush and convince the guerrillas it is safe to turn themselves in.

Simply known as Chris, the Front officer from Robert Mugabe's Zimbabwe African National Union has been invaluable in paving the way for the guerrillas to report, Hill said.

Chris is "completely committed" to seeing the cease-fire succeed and has worked non-stop to bring in the guerrillas, Hill said. Reminded that he had known the guerrilla officer fewer than 48 hours, the lieutenant said, "It seems like ages."

At first Chris would not part with his weapon as he felt his way among the British but now, Hill said, he is so relaxed that he often has to search for his rifle before going out in his frequent 20 mile runs "to speak to the masses."

The guerrillas who have shown up have mainly been in civilian clothes but "are very professional and well organized," Hill said.

The process of building up trust and enticing the guerrillas into the camps is painstakingly slow. After years of warfare in which thousands have been killed, they are like an animal lured by bait, moving in, pulling back, coming forward again.

Sgt. Hall greeted a lone guerrilla who showed up briefly this afternoon.

"Don't be afraid, come forward," the unarmed Hall said. The guerrilla hesitated, then took a few steps and shook hands.

Lt. Col. Les Hubble, the Australian in charge of the northeastern monitoring sector, said the fact that police escorts had to be used to bring in the British forces undoubtedly kept the guerrillas away for some time.

The rendezvous site, located a few miles from the village of Muchinjiki, is marked by a simple blue and white sign saying "Cease-Fire RV Point."

The school buildings are all marked by machine gun bullets and mortar hits. Few windows are unbroken.

Some of the classrooms bear evidence of Rhodesia's political wars. Chalked on the blackboards are slogans in the Shona language saying, "Down with Muzorewa" and "Forward with the Zanla forces." Zanla is Mugabe's army.

Lt. Hill gazed at the scene and said: "This must have been a beautiful place before it got ruined by war. Absolutely gorgeous."

Just then an African woman walked through the compound, carrying a basket of clothing and mangoes on her head, just as if there had been no war in the area.

The lieutenant recalled how last night about 300 Africans, including many guerrillas, had gathered on the other side of the rise and chanted and sang late into the night.

His troops turned off their transistors to listen. The war seemed far away.

Reality returned as Col. Hubble's helicopter took off.

An African boy, one of the many watching the proceedings with interest, started as the copter took off and then simply asked: "Will the war end?" Nobody had an answer yet.