Dick's information was accurate when it was posted. Since then, the allowance has been increased, so the 150k size images are now displayed, not just linked. 99% of images resized to 640 x 480 will be less than 150k as long as they are saved at the most common 80% compression setting.
The 150k limit is only for "File Manager" direct uploads to Shop Talk. Images hosted elsewhere (ImageShack, PhotoBucket, etc.) are not included in that limit. All images are displayed on the forum at a maximum pixel size of 640 pixels, such as 640 pixels wide x 480 pixels high no matter what their actual pixel dimensions really are.
All File Manager images are available from past years as long as the topic is available. Only a few topics have been removed because of rules violations. (We reserve the option that some older non-relevant topics may be removed in the future) Old images on third party image hosts are often deleted from the server because of low usage or time limits, especially on Photobucket. There are lots of useful images missing on older topics that were originally hosted on a third party image hosting sites.