Can one buy a 7 branch menorah found on Judaica sites? If so, what qualifications must it meet?
ב"ה Shalom, sorry for the delay. You rightfully asked this question. Your request for qualifications is actually very detailed and therefore I'm afraid I won't be able to supply you with the all information. Perhaps I'll give some guidelines and then if you send me a more detailed description, I will be able to be more helpful. What is clear in the Shulchan Aruch (יורה דעה קמא:ח), is that it is forbidden to produce a 7 branch Menora. There is discussion among the commentators if this prohibition includes not only making a Menora but holding one in your possession. Some say, that the reason to forbid holding it your possession is because of the suspicion that one may worship it and since no one worships a Menora, holding one in your possession should not be a problem. However, there are those who none the less forbid this. So one should be cautious. However, since there is a disagreement if we can at least be lenient when the qualifications for making a proper Menora are not met. So, one may be lenient to hold such a menorah in his possession, if the Menora is not made out of metal. Some say, that if there is no receptacle for oil, such as an electrical one it also permitted. There are many details in theTalmudic Encyclopedia ,[Hebrew] volume 30, under the entry of Klei Hamikdash, pg. 387 . All the best