Hi Charles.
I asked Andrew at Omicron about the gearbox, and he agrees that that this version doesn't have a synchro on first. So - at least it's not faulty. I might still think about temporarily swapping it for another box though. The first gear ratio is really high, and it makes pulling away on a hill a bit of a struggle and unfortunately for the clutch in this car, there's lots of hills where I live.
Thanks for all the replies.
Let me know if you need assistance. Piggyback is obvious from rear of g-box casing. Input shaft splines are coarser like S1 4 speed cf later 5 speed units. Ratios can be tested with gearbox out before disassembly. Competition cars had copper clutch units. Most competition cars (1969-1974) used later 5 speed housing with homologated gears.