I've always had a suspicion that those old releases as listed on the website were a fictional history of the band, a spot of misinformation cooked up for their own amusement and as a way of diverting the press when the band started in earnest. Remember, this is a band who hid the fact that they are brothers for many years, so playing with the public's knowledge of the band isn't unknown for them.
I think the 'Old Tunes' cassettes were as official and packaged as they got pre-Twoism.
I don't doubt that they made music earlier than Twoism. 'Old Tunes' are proof of that. However, I'm pretty convinced that we would have seen some evidence of those 'lost' releases by now.