Justas,
There is a very good chapter on ‘Love’ knots, which includes your reference, in THE HISTORY AND SCIENCE OF KNOTS by Pieter van de Griend and John Turner. ISBN 9810024699 - I hope you will be able to find this in a University Library in Lithuania, (it is expensive to buy) because it is well worth reading.
Although several variations of the so called ‘true lovers knot’ are depicted, there is no certainty that any one of these is the one in Chaucer’s Tales; it could be any one of them.
I know this is a very old thread, but while reading “Quipus and Witches Knots” I came across a section discussing the first reference to True Love Knots by Heraklas in the 1st century A.D. He describes it as a loop and two overhand knots which can be seperated or pressed close together.
I thought it was interesting to findsuch an early discussion of knots