What dimensions do you need that you can't measure? You just need to know its length and diameter. Diameter should be easy enough to figure out. If the frame is roughly the age you think it is, or even within a few decades, I'd assume it was designed for a fork with a 1" steerer tube, so you just need to measure its length to choose an appropriate fork. The fork's steerer tube will need to be longer than the frame's head tube by enough length to accommodate the stack height of your headset. If the fork's steerer tube is too long, it can be cut to fit. The steerer tube's unthreaded portion needs to be shorter than the frame's head tube. In other words, when the fork is inserted, all of the steerer tube that protrudes from the top of the head tube must be threaded.
Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Raleigh Pro, Trek Cycle Cross, Mongoose tomac ATB, GT Bravado ATB, JCP Folder
"196x369" could likely be the fork's lengths. 196 being the steerer's length from crown seat to top of steerer. 369 could be from the axle center to the brake mounting hole or to the crown race. These are easy to measure to confirm. "Akisu" is likely the OEM manufacturer. Many bike brands out source the sub frame components. Raleigh moved to Asian sourcing right about the time you say this bike is from. Or the fork could be an after market replacement. In any case a careful examination of the frame/fork for accident damage, age/stress concerns is warranted. Always be concerned about resprayed bikes. Andy.