The Medway Handyman wrote:

Spur type uprights have fixing holes at 250mm centres?

Spur is still imperial and uses a pitch of 1.25 in. The fixing centres
vary between uprights of different lengths, but will always be a
multiple of 1.25 in. On the 78 in. upright I'm looking at at the moment
it's 12 pitches, i.e. 15 in.

--
Andy