There ya go!
http://www.ebay.co.uk/itm/2-X-Olymp...y_VintagePhotoAccessories&hash=item3a848360d9
The serial number does not give you the date, it's under the sprung film tensioner inside the camera, open the film compartment and carefully remove the pressure plate on the back of the door, this is quite easy, It simply slides free from its locating pins. Look for a code on the back of the pressure plate.
The code consists of 3 characters:
1st Japanese character or letter (in later models) signifying the assembly plant.
2nd number representing the last digit of the year of assembly
(e.g. 5 = 1975, 0 = 1980).
3rd number or letter representing the month of assembly,
1-9 for Jan-Sep, X, Y, Z for Oct-Dec.
for example; N1Y = November 1971.
Of course the TRIP 35 was manufactured between 1967 and 1984, so if you are unsure if you have a 1968 or 1978 model, the chrome shutter button is the earlier and the black the later.
Hope this helps!