I've been skulking around on the auctions looking for a good sported A3 to convert into an "A4gery".
My first attempt netted me an SC that had been sported, but turned out to have the rear sight reverse dovetail ground off.
Second attempt was a very early SC that still had the original 6-groove barrel and may be too nice to further sporterize.
Third time might be the charm. I got this one for pretty short money and it seems to have some of the work needed for an "A4gery" already done.
Barrel has been cut, but I was considering putting a new Criterion on anyway.