Thank you so much for your detailed assessment of the position. My reason for believing that NOl's prior to 2015 might be lost was in view of the rule whereby 1040's as far back as 2015 only can be amended currently (and back to 2016 only after tomorrow!) where refunds or credits would arise. In the current instance it is in fact the case that no refunds or credits will arise for any year back to 2008 as a result of the amendments or indeed back to 2002 if amendments that for back are permitted. The purpose of the amendments in this case is to ensure that the just quantum of Net Operating Loss carryforward will be available into the future. Is it the case therefore that where refunds or credits won't arise for any year as a result of the NOL carryforward related amendments one may amend original 1040s even further back than 2008, even to say 2002?
Finally, would it be permissible in this instance instead of amending the 2015 return to show the correct accumulation (i.e. aggregation) of NoL carryforwards up to and including the 2015 return (as well as amending the later 1040s similarly) to instead amend the most recently filed return (for 2017 or perhaps 2018, if the requisite work cannot be carried out by tomorrow's deadline) and support the 2017 (or 2018) filing with the supporting calculations, summaries and worksheets you specified. so that in this instance the 2017 (or 2018) amended return may be filed to correct what should have been reported on line 21 had the original return been prepared correctly to begin with. This particular query is prompted by the fact that If there is no restriction which confines the filing of amended returns in cases such as this to the last four years, then choosing to adjust the 2015 return instead of the 2017 (or 2018) return appears arbitrary and perhaps unnecessary?