There's two ways to hold an EP in the focuser, friction fit with a sprung
end to the tube or use a holding screw.
You got used to one method and now are confronted with the other method. Of
the two, I prefer the holding screw method as that allows for the better EPs
to stay firmly in place.
I'll also note that the EP you have may also be smaller than it should be.
As to a decent focuser, I'd only consider Crayford focusers for the low
price field. Crazy Ed has had focusers of that type for $85 for a while and
probably still has them. Aside from that, it only takes an hour or so to
build a Crayford if you have the tools.

--
There are more Democrats on the Calif. Special Election than Republicans!
Go count if you don't believe me!
Bob May