I'm not finding anything on line for a Altec Lansing 541B. This is a very documented brand, especially the old, really good stuff. I have some of the A7 500's that are not marked anywhere (that I have noticed) with the model number. It just says Voice Of The Theater on a big decal and speakers and horns are all numbered and it list the ohms. For example 1 set of horns is labeled 511B. My oldest pair was bought in 1958 by the original owner had never assembled. They sound unbelievably wonderful, I just had to break them in. Nothing has been done to them and they are over 60 years old. As long as the mice or sunlight haven't effected them, guessing you can hook them up and they will probably sound as wonderful as the last time they were played. You might have capacitors in the crossover that you might want to make sure there is no swell. Can you post a picture of the speakers? To give you an idea of value, these are Model 14's for sale in Louisville, KY for $1,750.