Actually, an idea just popped into my head.
If you're up to doing something a bit different, you could use Brackets - free and open source - in combination with Chrome - again free, but not wholly open source - to edit an HTML file in Brackets while getting a live preview in Chrome of how the text will look. Make the Chrome window about the same ratio as the page you'll be using and you'll get a decent basic idea of how it will look when printed.
The code below gives a simple example of what you can do and an example screen-shot is attached.
Just import the HTML into Scribus as plain text and strip out the stuff you don't need. (You can search/replace the <p>'s and </p>'s away very easily to leave you with just the text you need.)
I've not actually used this myself - as I say, it just came to me - and I'm not sure how well it will work with a long book, but I think it's something that I might try if I need to.
<html class="no-js" lang="en">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0">
<style>
cno {
display: block;
font-family: "Times New Roman", Times, serif;
text-align: center;
font-size: 46pt;
margin-bottom: 20pt;
}
cname {
display: block;
font-family: "Times New Roman", Times, serif;
text-align: center;
font-size: 26pt;
font-style: italic;
margin-bottom: 24pt;
}
p {
display: block;
font-family: "Arial", Helvetica, sans-serif;
margin-bottom: 8;
text-indent: 12;
font-size: 12pt;
}
b {
font-weight: 600;
}
i {
font-style: italic;
}
</style>
</head>
<body>
<cno>1</cno>
<cname>This is the fourth chapter</cname>
<p><b>Lorem Ipsum</b> is simply dummy text of the <i>printing</i> and <i>typesetting</i> industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of <i>Letraset</i> sheets containing <b>Lorem Ipsum</b> passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>
<p>Contrary to popular belief, <b>Lorem Ipsum</b> is not simply random text. It has roots in a piece of classical Latin literature from 45 BC, making it over 2000 years old. Richard McClintock, a Latin professor at Hampden-Sydney College in Virginia, looked up one of the more obscure Latin words, consectetur, from a Lorem Ipsum passage, and going through the cites of the word in classical literature, discovered the undoubtable source. Lorem Ipsum comes from sections 1.10.32 and 1.10.33 of "de Finibus Bonorum et Malorum" (The Extremes of Good and Evil) by Cicero, written in 45 BC. This book is a treatise on the theory of ethics, very popular during the Renaissance. The first line of Lorem Ipsum, "Lorem ipsum dolor sit amet..", comes from a line in section 1.10.32.</p>
<p>It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here, content here', making it look like readable English. Many desktop publishing packages and web page editors now use Lorem Ipsum as their default model text, and a search for 'lorem ipsum' will uncover many web sites still in their infancy. Various versions have evolved over the years, sometimes by accident, sometimes on purpose (injected humour and the like).</p>
</body>
</html>