A few words should be added for clarification.
The OP and readers will remember that the peep sights are removable and so not an issue if someone desired to use optics. As they are part of a complete rifle, the fact that what appears to be the original sights should be seen as a good thing, the same with the hand stop. While they may not add significantly to the value, original parts are always more desirable than not. An Anschutz collector may find this rifle especially attractive.
The fact that it's an older rifle (from 1975) is not itself a problem as far as its accuracy performance is concerned. Many, many older Anschutz rifles, even older than this one, will still shoot very well. As noted above, a 1413 stock can be used for bench shooting. See image below sourced online (ignoring the front rest facing the wrong way and the absence of a rear bag).
Whether any competitive shooter would "get a modern BR50 with a space age look stock..bloop tube..and tuner," he would know first of all whether he was shooting benchrest or position. A BR 50 stock is for benchrest only. Any space age look stock seems like the aluminum ones for position shooting as is a bloop tube. A tuner is best used for BR shooting.
The barreled action can be used with any Anschutz Match 54 single shot stock, including the Anschutz BR 50 benchrest stocks and modern aluminum Anschutz stocks.