modifying postscript file: shifting content and resizing page or crop content

I have a program that produces postscript file. The file has a text block vertically in the middle of an A4 page.

The text block fits A5 size in landscape mode. I would like to convert the ps file from A4 size portrait mode to A5 size landscape mode by shifting and/or rotating the text.

I tried to use pstops tool:

pstops -w14.8cm -h10.5cm 0(0cm,-7.5cm) file0.ps out1.ps

which gives:

or

pstops -pa5 0L(25.3cm,0cm) file0.ps out2.ps

which gives:

It seems that pstops crops the original A4 size to A5, and only after cropping it shifts/rotates the page. Therefore the original text block is cut and only part of it goes to the new ps file.

Is there any way I can solve this? Need not to be pstops but have to be done automatically without user intervention in a script. If it takes more steps and/or tools it’s OK too.