I was in the Boston area in late June and had an opportunity to spend a little time with the people at Fidelity Management Group, the financial services company with something like 21 mutual funds, a discount brokerage service and an investors' asset management account.

The main purpose of my visit was to get a look at their new walk-in financial service center. My timing was bad--I missed the formal opening (and the cocktail reception for the press) by three days. But the center was already open and I had a chance to observe it in operation.

The company was almost forced into the center by pressure from their clients. They were seeing as many as 500 walk-ins a day at the small service desk on an upper floor in one of their office buildings in Boston.

The large counter across the back wall of the new center is manned by a half-dozen or so registered representatives who are qualified to answer questions, offer advice and handle transactions for any of the company's financial services.

High on a side wall is an electronic sign flashing up-to-the-minute investment information. Computer terminals provide a question-and-answer format for visitors to the center who aren't yet ready to talk to a representative.

Perhaps the most interesting innovation is an automated teller machine where investors in Fidelity USA (the asset management account) can get cash from their associated money market fund 24 hours a day.

During the coming months, the company plans to open similar centers in Dallas, Chicago and San Francisco. Any further expansion will depend, of course, on the results achieved in the first centers. Judging from the response I saw in Boston, this new service concept will be welcomed by investors.

Fidelity's new Boston center is not the first of its kind. In March, Stein Roe & Farnham opened the Stein Roe Fund Center in Chicago to provide convenient customer access to information about the Stein Roe no-load mutual funds.

Here, too, representatives can offer information, answer questions and handle transactions for present and potential investors in a convenient street-level location. And Stein Roe & Farnham has a "Transaction Station" in the lobby area that is open 24 hours a day, seven days a week to accept instructions for purchases, redemptions and exchanges for any of their funds.

The once-sharp lines of demarcation separating savings institutions (banks, S&Ls and credit unions), brokerage houses and investment companies are becoming even more blurred, and we are moving ever faster into the age of the financial supermarket.

Question: In May, I sold rental property in Ocean City that I had bought in 1964 for $37,000. Each year since 1964, I have been deducting, among other expenses, depreciation on the four apartments and on the furniture. How soon do I have to report this sale? Do I wait until next April 15? Is the depreciation that I have claimed each year added to the base cost or subtracted from it?

Answer: You report the sale on your 1983 tax return, which is due next April 15. But if the gain on the sale will materially increase your taxable income for the year, then on Sept. 15 you should file an estimated tax return and pay a portion of the increased tax that will be due.

To arrive at the adjusted cost basis from which to figure capital gain, you must subtract the depreciation taken over the years from the original cost. At the same time, don't forget to add the cost of any capitalized improvements and additions made since 1964.

This is true only of the depreciation taken on the structure (and any capitalized improvements), not on the furniture. The original cost of the furniture should not have been added to the cost basis; instead, it should have been amortized (depreciated) over a much shorter time period than the structure, as a current expense.

If you sold the furniture, too, that sale should be reported as a separate transaction. If it was included in a single package and can't be broken out, then you will have to go back and pick up the original cost, add that to the cost basis (if not already included), then subtract the furniture depreciation as well as the depreciation on the building itself. I suggest you see a qualified tax consultant for help.