Managing 301 Redirects correctly in FlyNax htaccess file

[Tim Wade]

Hello:

I have just converted a long standing live classifieds site to FlyNax version 4.6.1

I am now trying to manage the hundreds, and even thousands of broken links.

I would normally do this with .htaccess with a Redirect Permanent statement.
For example:
at the very bottom of the .htaccess in the root of flyNax installation.

I have

RedirectPermanent /Home/ClassifiedsAds/163/ https://www.concreteiron.com/classifieds.html

But this statement does not seem to have any affect, and it just goes to a FlyNax generated 404 page.
OR it will take me a "site cannot be reached" page, which seems to be breaking the whole site.

How can I manage these redirects correctly?
What am I doing wrong?
Is there some different way to do this?
I have hundreds of them.
I dont want Google to report them as broken or soft-broken...
What is the best practice for managing 301 redirects in FlyNax?

I have seen other shopping cart and e-commerce programs such as Magento that actually put these in the CMS and allow you to define redirects in the database, and this is very nice.

and it is critical that I save all my existing traffic on the site, to keep my search results high and the traffic coming.

What is the advice?