They are...a couple of years ago they could be found on E-Bay for what seems like a steal today...I bought 10 or so 17's and 17A's made for 1903's, 1922 's , and 03a3's ...I was paying $50-$75 and was complaining for a year... now you can add another $100.00 if you can find one...as for the 48s ditto...they still pop up but are up there in price...are they worth it..yep....