We can trace what early ante-Nicene church fathers believed and especially ones that were from the first and early-second century were almost exclusively ECT.
This bald unsupported claim is merely asserted, like the claim "there is a tooth fairy", without any evidence or proof.
If the translators falsified their translation then all knowledge gained through revelation of the scriptures is suspect!
If many translators ignorantly (or purposely) translated the Scriptures into English based on their theological biases, instead of by an objective standard, does that make most or all of our English language Bible translations suspect? Of course it does. Do you blindly believe that these - opinions - called translations of the Scriptures are infallible, inerrant & inspired? Are they like a substitute infallible pontiff to you? Or would that be your pastor?
Furthermore, the original Scriptures are not known to exist. There are many manuscripts of the ancient language texts surviving. These are written in ancient languages, especially Hebrew and Koine Greek. Any translations of these "Scriptures", if you will, into English are merely - opinions - of what these "Scriptures" say. These English opinions, called translations, of the "Scriptures", disagree with each other in numerous points. There is also disagreement re which of the ancient texts of these "Scriptures" are more accurate, as there are many differences between them as well.
Moreover, as to your reference to "all knowledge gained through revelation of the scriptures is suspect", a non Christian considering the 100's of denominational divisions & doctrinal differences re interpretation of "Scripture" in Christendom & groups that call themselves "Christian", might wonder if that makes "Scripture" & Christianity "suspect". Without the Holy Spirit, how can one come to a knowledge of the Scriptures? Is that something that comes by man's self effort, or by revelation? Is knowledge of the truth of the Scriptures a "knowledge gained through revelation of the scriptures" or through a revelation of the Author of the Holy Scriptures, the Holy Spirit?
The ignorant translators biased to the endless hell dogma rendered terms (olam, aion, aionios, etc) that can & do - often - refer to finite durations as "eternal", "forever" & the like in contexts referring to eschatological punishment. Thus, they rendered them according to their theological position. What they should have done is translated them as theologically neutral terms, e.g. eon, eonian, which can refer either to a finite or endless period of time. And left the interpreting up to the readers whether or not, in any given context, the words "eon" & "eonian" refer to a finite or endless "eon" or "eonian" duration. But, instead they injected their opinion, their interpretation, of terms (such as olam, aion & aionion) into the text. Thus you don't have a faithful translation of these words with most English translations, but rather an interpretation, a paraphrase, a theologically driven opinion.
That is why is see the approach of qouting passages whether they be Greek or Hebrew, Latin or Coptic, Syriac or english, if we say "I want the secondary, or tertiary meaning to be inserted in a text as a translator then what would keep me from doing the same about every text on every theological issue I didn't agree with?
The fair way to translate (olam, aion, aionion, etc) is to use an English word (e.g. eon, eonian) that covers the range of meanings for that term & leave the interpreting up to the readers. Rather than inject one's theological biases into Scripture's ancient language words that have multiple or ambiguous meanings. If an appropriate English word is not available, then there is the option of using the ancient language word, i.e. not translating it, as some versions have done, e.g. using aionion. Or just transliterate it into English, e.g. eonian (or alternately aeonian, agian, etc.).
Secondly who's to decide that "eternal" is the primary meaning of aion or aionion or olam? That is much debated among scholars.
Not just translators falsify! On this approach copyists and editors would also change texts.
And if they did? We have thousands of ancient Greek manuscripts, in addition to quotes in the early church fathers, to determine what the original Scriptures said. Still, there are differences between them which are debated & considered significant. Most notably related to the debate between the KJV Only advocates & those who prefer more modern versions like the NIV & NASB.
Furthermore, BTW, there are various significant differences in Christianity concerning what books even qualify as being in the Canon of the Scriptures.
This is the ole cutting of one's nose to spite their face routine.
How is that? Do you consider the KJV opinion infallible, inerrant & inspired? Which Canon of the Scriptures do you consider to be "the Sacred Scriptures"? The Roman Catholic Church version, the Eastern Orthodox version, or one of a number of other versions?
