Sjobergs bench

[Brian Tierney]

I have ben lucky enough to find a small Sjobergs bench with a shoulder vice and tail vice , older design but in remarkably good condition. One problem though, it was supplied with two M8 threaded rods to attach the top which are clearly not original fixtures, these only partly screw into a captive nut on the underside of the top and I do not want to strip those threads.
Does anyone know what the original thread size is for these old models, Sjobergs have not yet responded to this query? One more thing when I oil the top should I do the same to the underside

in the interests of balance (Danish oil on a Swedish bench is not going to cause any friction in international relations I trust) ?