Thank you Guys, for very useful replies. There is a lot to think about here , all the options you mention are interesting and all would obviously improve my system . I have been looking at the specialist websites including FLO . As I mentioned , I am on a budget (hopefully of shortish duration !! ) and am initially interested in FLO's advertised 2X Barlow at £25. I think that would do the trick for me. Alternative suggestions are nevertheless tempting but going into a zoom eyepiece would be, for me, far too ambitious. My Astromaster 76, " kit " included an erecting lens which I have sometimes used with the 20mm eyepiece but I never found it absolutely necessary.
Many thanks to you again.
Pete