Degaston, since you were a former member, you know that often the way Joseph Smith received revelation was AFTER learning about something, and then specifically seeking answers about it from God. This holds true with Baptism, the priesthood, Word of Wisdom, etc, etc, etc.
ASK ye shall receive, SEEK and ye shall find, KNOCK it shall be opened unto you.
As far as Masons and "reputable" scholars tracing their heritage back to the medieval, era, there's likely some truth to that, most Masons don't know what they had, although there are many that claim a Solomononetic link, but as far as the specifics of rituals and ordinances of the temple, they can be traced back as far as God has spoken to Man on earth.
Here are a couple excellent treatises on the subject of ancient Temple worship and Masonry. They are among several that I have found that explores the ancient rites of the Temple. I have more if you are truly interested. I hope you will take the time to read this, it's pretty thorough, and gets right to the heart of apparently why you decided the Temple was a Masonic fraud. If you are an earnest seeker of truth, please read these:
Actually I am a current member of the church. In fact I'm a High Priest. I just happen to be a church member who isn't afraid to be honest. I will defend the church when they are honest. And I'll be honest about situations where its obvious that they aren't.
>> you know that often the way Joseph Smith received
>> revelation was AFTER learning about something, and
>> then specifically seeking answers about it from God.
When was Joseph Smith ever given a revelation that he should be justified in committing plagiarism? When has the church ever officially and properly attributed the elements of the Endowment that came from Masonic origins? If they haven't done this then they've committed plagiarism and they're still doing it to this day. Go read the definition on plagiarism from a dictionary and you'll have to agree that this is what it is.
BTW the shields-research.org and fairlds.org are not and have never been official church websites. And considering all the times that some Mormon apologists are so quick to dismiss or ignore a sermon from Brigham Young or some passage in the LDS scriptures or Journal of Discourses or even the Milennial Star or 7-volume History of the Church set that doesn't fit well with their 21st century worldview it's pretty important that when it comes to Mormonism that we get officially sanctioned information on important questions.