Offer your thoughts or opinion on the input financial query or topic using your financial background.

Does a 1045 exchange require any filing prior to that years tax return?
When you get into reading Revenue Rulings and Treasury Regulations - I'd suggest hiring a professional to do that for you. Especially since you also need to assure that the new stock does indeed qualify as QSBS. However, from the revenue ruling you quoted it doesn't sound like there's any other requirement other than reporting the subsequent purchase as a loss on your schedule D. I wouldn't know, however, if there are subsequent/superseding revenue rulings on the matter since 1998. Professional tax adviser (EA/CPA licensed in your State) would have the means and the ability to research this and give you a proper advice.