Vintage Dual 1228 Turntable : worth to upgrade cartridge ?


I have from my college days (1977) Dual 1228 with original fitted Shure M95ED cartridge .  It is maintained well , not used for about 20 years in between , but just cleaned , lubricated , resoldered some loose connections , etc and just runs great for me. 
I am not too much into analogue , so not planning to do big time investment into new TT , Phono preamp , but if  can get larger benefit by replacing the Shure M 95 ED with some new cart upto $ 200-300 , I would like to do it . 
My Phono preamp is very low end Cambridge Audio MM 551P . To go with new upgraded cartridge , I may even consider to buy used Phono with budget of $1000 . 
I would appreciate advice form FMs here , where I should spend my money to get most benifit on sound improvement . New cart , new phono ? 

radni
Since you already have a Shure on the arm now, I don’t think you would go wrong replacing it with another Shure. I can’t give you a comment on the AT as I don’t know how it will work with the Dual arm.
You can be sure with the Shure!
+1 yogiboy
Would you put on a set of high end Michelin tires on a 1977 Chevrolet Vega?
Makes no sense to spend more than $100 on a cartridge for a 40 year old Dual table !
The Shure is fine.
Yogiboy,
That Shure M97XE looks exactly like my V15; I think they just changed the name. That brush is highly functional; it enables you to track warped records, and it also prevents "dust bunnies", I'm sure that would work perfectly on a Dual TT.


Enjoy the music.
I have owned a number of older Duals (and liked them) and in their day, they were very well respected. Shure cartridges always seemed a nice match. I've used M91ED, M95ED etc. For your purposes, the 97EX is fine or maybe the Ortofon Red
I just ordered a JICO Stylus SHURE N95HE ( Hyper Elliptical ) which will fit onto my current cartridge M95ED , I hope it should give sound improvement. It should arrive within a week.  I will order a new Cart Shure  M97 or AT soon. 
Thanks to you all FMs , for your valuable help to understand this issue and make a decision. I was kind a shaky to start this topic or ask here , but I am happy to note that FMs have been very forthcoming in sharing their experience, knowledge and helping . That's what I like about this community.