As far as I know, "fabric (fabrication?)" refers to the Ardboe High Cross, which dates from the 9th/10th century.

This was one of the big songs sung by the great Geordie Hanna, who came from this area of Tyrone.

I've also heard this verse:

"In summer evenings for recreation
You can careless wander along the strand
Where Bora's breezes are gently blowing
Around the spot where the fabric stands
It was St.Patrick who did ordain it
That great stone cross to be raised on high
As a reminder to simple Christians
That on the cross God's son did die"

Regards
Joxer