[cafe]

I make all S&P recolors with Inkscape in Bruno's original 1:300. When it's done, I group everything together, select the group and just use Inkscape's resize feature.

See screencap below. Notice the yellow highlighted icons above the drawing area?

1) lock the padlock so that resizing applies identically to length & height
2) select % as a unit
3) select the group of objects you want to resize
4) type 150 in either the length or height box and press "enter"

To go from 1:300 to 1:200, the scaling factor is 150%. To go in the other direction, it's 66.6666%.

Sometimes I use different percentages because I feel the model is lightly overscale (145% for the Mirage 2000 and F-5A, 135% IIRC for the Jaguar).

If the resized model exceeds the width of the page, I flip it by 90° (the icons for that are on the same toolbar) and then center it vertically and horizontally on the page. If it still exceeds the page limit, it's time to ungroup and rearrange the parts, maybe use a second page. Once it's done, save as svg, then as pdf.

If you're using a different vector program, it probbly has the same feature (and probably allows for multiple pages unlike inkscape even if I put a lot of things outside the page frame while in designing mode).