This link goes to a download for a ZIP file (couldn't attach it here directly due to size limitations) with all revisions of skinning and scripting documentation for MP!L archived so far, which were published in .chm format. You can either download select revisions or download the entire ZIP and extract it on your computer. If you have any issue opening the documentation (almost a given for those running Windows 8 and higher), go into the file's properties and check "Unblock" before applying changes and opening. Below is a list organizing each document by whether it's for skinning or scripting, listing its revision date and minimum MP!L version it was written for.
- MPLScripting_20090302.chm - last updated March 2nd, 2009; written for MP!L 4.81
- MPLScripting_20110128.chm - last updated January 28th, 2011; written for MP!L 5.00
- MPLSkinning_20110131.chm - last updated January 31st, 2011; written for MP!L 5.00 (most of the concepts discussed I believe should still be able to carry over to 4.xx)