6 channel rx is an FM rx
2 channel Tx is AM
so I don't think that it will work for you.
Note also that Futaba make the 2ch Tx both as 27 and 40 Mhz versions,
and these are not interchangeable, you must have the right crystals in the right Tx
New Rx is not too expensive, and it's worth spending a little money to be sure that
your pride'njoy doesn't go careering away to end up as a pile of bits.

Edward.