Just my 2 cents (euro of course) regarding Grotors: When/if you plan to machine the parts, pay particular attention, cause it's probably made out of powder metal baken (don't know the english word for that), and it may be pretty hard and brittle...
True, but I will give machining the parts to length a go, and if my search with the "Hoover" fails I will copy John's original parts as templates in anti-mag SS using electro-erosion. We have this facility locally.
I will most probably get the parts in the correct length from a catalogue as these are normally standard parts.
All the best.