From an 0.10.x site, a simple PageMaster page looks:
The page constists of two sections. Each section has a flag image associated. The placement of the image is controlled by the assigned template.
Old page source
Let see the source ...
Old section source
... and the source of one section ...
As seen, a flag image belongs to the section and the placement is controlled by image_float_left.tpl with the effect, the image is placed first and left, with the ajacent text floating around at the right side. The view was shown far above. As most usual in pWS, the image(s) were uploaded and only in less cases referenced by native html img tags. In pWS 1.0.0, images as content in WebPages will not uploaded, but referenced by html tags, and placed in the images path of the site, like ./images/.
As mentioned in the readme attached to convert, to have the images at the right place is the responsibility of the author and convert does not have any tasks to handle the images. Lucky people have kept their images at any local place and, in this case, they only need to transfer the images to the new sites image path.
Others, not more owning the images anywhere else, can take the images from the old site to the new one and have to know, where the images are kept. Because of the former upload field, it could be assumed the images are placed in the database. But that is not the fact. Instead, the former upload dialog made yet an entry in the database, but only as reference. The images itself where placed in the file path of the module PageMaster and there the images are still to find: ./images/pagemaster/.... In the worst case, you have to transfer the images from the old site to local, and from local to the new site. When ssh access is possible to the site, wget would be the smarter and easier way to do this job faster within one interaction.
Converted page view
Let have a look to the new, converted page to find in WebPages:
Converted subpage source
There are no flag images to see. The reason is, the images are not yet transfered. Let have a look to the new source in pWS 1.0.0 ...
Converted subpage source (html)
... and to the html source of FCKeditor ...
The presence of the images in the html code is given by the img tag, as to see. Because the images are not yet transfered, the alt tag have the effect instead (... I appologize to everybody disturbed about the UK flag named as US ... was a stupid fault). Now transfering the images.
Final page view
The flags are not placed as origin, but that becomes easy repaired by interactive rearrangement of the images in FCKeditor (only draw the images by mouse manoervres to the place you want).
Pages converted, conclusion
As mentioned above, webpages in pWS had and have IDs. If no webpages still exist in the new site, the IDs from the old site pagemaster pages will taken over without conflicts. But if webpages just exist, the behaviour about IDs seems not to be unique. In that case, I experienced some pages became not converted and some old pages changed the IDs. Following Matt's suggestion to convert into empty, is the best choice in any case.
Pictures used in pagemaster sections were controlled by assigned templates. Such equal templates does not exist in webpages (and cannot exist, regarding the new logic, images are not more controlled with the database). Some work is required, to place the images where wanted to appear. With FCKeditor, that handling is most easy (hire your children to do this :-).