Rhodesia Cylinder Block Query

Query on RHODESIA XV World Ploughing contest cylinder.
G'day all,

Is it usual for the colour dots box to be the same size on all the sheets in the set even though one has only 3 colours rather than 4. ?







The majority of my examples of cylinder blocks are of G.B. and they match
the size of the box to the dots as shown in the Post Office Tower block.







Cheers
Penguins

Ron,
just thinking aloud,
for that corollory to be true, you would first have to establish
both emmissions were from the same printing machine.
I trolled my database for "traffic lights" but I have mainly Aussie
examples which are not boxed.
They exist as a registration and colour guide, and I presume yours would date from the time of the "crown agents" and they may
have used two differing machines.
One would presume the box would remain to accomodate 4 traffic lights
to comply with most issues employing 4 colour passes.

PS. interesting example of an early plough on the Rhodesian.
never seen one before driven by human power.

According to Gibbons, the Rhodesian stamps were printed by offset-litho by Mardon Printers in Salisbury, but if memory serves, the UK issues were printed by photogravure. So certainly different machines.