He said he hoped it would be put back into the wall, perhaps with another business card with the current crop of builders' names on it.
"It was pretty neat to find it and we would like to see it carry on being inside the wall. It should be a long time before someone finds it again as this sort of work doesn't happen that often."
Last month, the pavilion was moved from its old home on the Karanema Drive side of the Havelock North Domain to the Te Mata Rd side of the park, where the public space is being rejuvenated and renamed the Village Green.
The pavilion was going to be left where it was until the public asked for it to be moved to a more central position, and offered to fundraise half the estimated $300,000 it added to the $1.5 million cost of the project.
Most of the extra cash had been raised and the building was moved into its new position on August 31.
One wing of the building will house the Toy Library and Plunket while the other will be new public toilets. On the park side, stepped down decks into the park are being added.
Most of the new facilities were expected to be completed by mid-December, weather permitting, said Hastings District Council parks manager Colin Hosford.
Public consultation on what to include in the Village Green was held last year. The plan includes a new playground with children's water play area, sun shades, a revamped skate area and new seating and tables, and built-in chess boards.