The WP residence period I have a doubt about is the time between 16/03/2008 & 27/05/2008. I.e. looking at the information provided it appears that you did not have valid leave to remain during this time period. To add to this, as your subsequent LTR application was technically submitted after your LTR had expired, it would have fallen under the out-of-time application category. Meaning you would not have been covered by S3C during the period between 27/05/2008 & 04/08/2008, resulting in an overall overstay period of 16/03/2008 to 04/08/2008.
According to the following WP extension guidance, employers are requested to "apply at least one month but no more than three months before the applicants current leave to remain expires". In your case it appears that your employer left the application rather late, i.e. submitted it quite close to your LTR expiry date. I.e On 06/03/2008, which was 10 days before your LTR expiry.
I haven't read the following guidance in detail, therefore will leave you and others who know more about this to either read or comment further. But based on points 125 & 127 you would not have had the right to work during the period 16/03/2008 & 04/08/2008.
http://webarchive.nationalarchives.gov. ... de0408.pdf - Page 13.
125. If a work permit extension application has been submitted, the individual may continue working with you whilst this application is being considered provided they either:
• continue to have valid leave to remain; or
• have submitted a further leave to remain (FLR) application before their existing leave to remain expires.
126. Details of how and when an individual should submit an FLR application, for the purposes of extending their existing leave in line with a work permit extension, are provided under Section 5 of these guidance notes.
127. Where neither of the conditions detailed in paragraph 125 are met, an individual should not continue to work after their leave to remain has expired whilst we consider the work permit extension application.