Cryptic Clue

Having been built in 1367, the spire of St Mary's, Bridgwater has required repairs from time to time in the centuries since. Those of 1694 are commemorated in a plaque - but it's rather cryptic. First, it's on the side of the spire itself so reading it from the ground requires excellent eyesight. Second, the text is very economical: 'G B/H P/1694'.
This type of inscription always intrigues me. Were those responsible too modest to add more (although too proud to resist altogether)? Were they arrogant enough to think that everyone would always know just what those few letters and numbers meant? Or were they simply limited by space and money?