No originals remained how is that known to be legit?
Wycliffe did use Jerome's Latin version but also the Greek, Hebrew and Aramaic translations. A English translation for those beyond the church walls. The catholics were not happy about it at all to the point of digging up his body and taking the remains from the cemetery, kind of immature to say the least.
I found this info below interesting,
The New Testament has been preserved in more manuscripts than any other ancient work of literature, with over 5,800 complete or fragmented Greek manuscripts catalogued, 10,000 Latin manuscripts and 9,300 manuscripts in various other ancient languages including Syriac, Slavic, Gothic, Ethiopic, Coptic and Armenian. The dates of these manuscripts range from c. 125 (the 52 papyrus, oldest copy of John fragments) to the introduction of printing in Germany in the 15th century.