Rick Rudd Vessel and mark

I have this little Vase type vessel, it's stamped and from what I can find out it probably dates from around 1978, or am I completely off the mark? I would like to sell it, should I just pop it on trade-me or put it in a specialist auction? I can only seem to find information on his recent pottery values so have not idea if these early pieces are desirable or not. It's only 16cm tall.

Fantastic to see a photos and yes this piece would be admired by many even though it's a bit patchy.  Raku does oxidise in sunlight. It's hard to tell when it was made as he used this style for many works.  That is definitely Rick's mark.

Thanks for your reply. It's not actually as patchy as it looks in the photo, some weird light refraction was going on there perhaps.