No worries. First the serial, it's WF00969. The frame is one of those pink and dark-grey Internationals that came with Suntour Sprint, same as here

The first bike I got was the blue and silver one, which had the 27.2 spec seatpost. I had problems with it slipping and probably should have shimmed it, but anyway ended up cracking the clamp area. When I took it to get repaired the frame builder (who did a nice job brazing a new lug up) said that the tube measured out much closer to 27.4 than 27.2 which would have caused the issue. I bought a 27.4 seatpost and rode the bike for a couple of years before selling.
I then found the current one on the facebook trader, cheap as it had no groupset. I bought it knowing the possible issues, and sure enough found that it was starting to crack by the clamps. I made a shim for a 27.2 seatpost and rode it for a while before buying a 27.4 seatpost which fits very nicely.
I should add that I am in New Zealand, maybe bikes for the Oceania/Asia market were finished differently in a different factory or it's just they were made on a friday afternoon just before clock-out time