Hello and welcome. Lons has a fair amount of knowledge on these and will do doubt be along sometime soon,
and pass on the instructions that he has.
I believe The earliest Woodmen K5, had a white, splay legged base and white machinery, with, as you say yellow guarding.
The motor has a year on the plate, on it's side, inside.
which means taking off any drive belt and looking between the motor and saw base it's attached to, a small mirror will be handy!
Spares are very rare but the machines go on very well and suffer from neglect and non use mostly.
Saw blades and planer cutter's are still available
The early spindle shaft is rather small at 15mm, and has to be said the slotted collar system is rather dangerous!
The next later Woodmen K5,(All made by Kity) had square larger legged base still white, and the guarding either yellow or red, With the spindle shafting now 20mm.
They don't fetch big money, but for smaller jobs, are very useful indeed.
HTH Regards Rodders