First job this week was to make new gaiters for the rear brake servo.  These are now awaiting the attention of the seamstress.  After that, I touched up the paint on the cab door window with undercoat.  Progress slowed a bit then, but some scraping and cleaning of the chassis and mounting bracket for the servo was carried in preparation for paint and the servo forward mounting block through-bolt was cleaned and made a better fit in the servo.   A little relief of the servo appears necessary, too, to ensure that the block allows a little adjustment of the servo horizontal position.  With the arrival of a 1/8″ WW spanner as I able to remove and dismantle the distributor valve, which was stuck solid, so I gently freed it with a combination of BDX and carb cleaner.  I was unable to fully withdraw the piston, as the rubber end seal at the rear had enlarged slightly with use, but the seals appear in satisfactory condition and the piston moves freely.   I made a new end cover and valve mounting gaskets, then lubricated the valve with DC4 silicone grease and reassembled it to the servo body.  Last job of the week was to make a 3.5 mm spacer for the adjustment lock nut on the valve operating rod in order to correctly set the clearance at the valve body as stated in the manual.