sewing machine (Hockley SS5)

Frister Rossmann sewing machine.

I have never used this myself but I understand that it was in perfect working order before being put away and not used for 20 years or so.
I have plugged it in and the light came on / motor was running but it appears to have seized up from lack of use and oil.
I gave a a bit of WD40 in the obvious places and it seem to be freeing up but not enough to use yet.
I think it probably just wants someone to take the cover off and give the moving parts a good clean and oil.
It's an old but good quality machine, I was thinking of giving it the attention it deserves and swapping it for my Toyota machine as it looks like a better one - But I just don't have the time.
It looks like it will do zig zag and possibly blind hemming too - if you can get it moving.
Obviously someone competent should check it is electrically safe.