One thing I'll need to consider is that the dates at the time of their baptisms/christenings may not have occurred in their first year of life. they may have been already 2 or 3 years old - which could allow for the difference in what I'd percieve their ages to be at the times of the Census's and at death. When I get a chance I'll try and look these deaths for Thomas and Christian up at the Family Research centre nearby. Is there any on line access to these burial records?