AFL-CIO President George Meany the old warhorse of a half-century of labor's politieal battles, went to Capitol Hill yesterday for combat over the administration's labor law overhaul package.

But it turned out to be a legislative tea party, with the 33-year-old guest of honor being feted with white-gloved deference even by those who have shaped a politncal career by running against nearly everything the old labor chief stands for.

The scene was the House labor-management subcommittee, where a kind of combative camaraderie prevails between friends and foes of unions that Chairman Frank Thompson Jr. (D-N.J.) has for the ranking minority member, John M. Ashbrook (R-Ohio). "Trashbrook," he calls him, sometimes even during formal sessions. Ashbrook smiles and gets even.

Meany gave the subcommittee the full treatment, sitting flanked by his heir-apparent. Secretary-Treasuret Lane Kirkland, and the AFL-CIO's chief lobbyist, Andrew J. Biemiller, as he read through every word of his 10-pages statement - a formality that others are encouraged to dispense with.

Gradually a thin cloud of cigar smoke veiled the threesome, as women's rights leaders - labor's new allies in the strange world of legislative coalition-making-filled most of the scars in the hearing room, waiting their turn to be heard in support of the labor bill.

Meany appearances are fairly rare on Capitol Hill. This one underscored the importance that unions attach to the legislation, which, through a number of largely proceduarl changes, would make it easier for unions to organize and win contracts.

The bill is not a union power grab as its foes have changed. Meany contended, but rather a "means of bringing democracy to the job." Then he added: "And while democracy may not be the most efficient system, it sure beats those systems promoted in the name of efficiency. In fact, Mussolini had a system the NAM (National Association of Manufacturers) might want to try. But I don't."

Like so many others, this invitation to a good fight passed by.

Later Rep. John N. Erlenborn (R-Ill.) suggested, even so politely, that Meany & Co. were living in the past. Meany, in response, somehow made the observation sound like a compliment. When Ashbrook rattled off a list of labor law violations by unions to match Meany's roster of industry scofflaws. Meany agreed emphatically that no one should ever violate the law, diffusing that argument as well.

Several committee aides said afterward they weren't surprised by the ritual. "There's a real deference to age up here," said one "You don't attack a legend," said another.

But Meany may have been a little disappointed. An aide remarked to him on the way out that it wasn't like the "good old days." No, Meany responded, "I was looking forward to a little combat, a little fun."