Hey Oskar,
Welcome to AudioCircle

I view with a sigh the cost of what starts life as a Grado Black ($40 here in US)....becomes an $1895.00 cartridge in the form of the Music Maker Classic (don't know if you're a Brit, but it's 1000 pounds over there

)
All the Grado's make music (coherent, natural, dynamic) - swapping out the (admittedly cheap) Grado elliptical stylus for a proper, lower mass line stylus, substituting 150' ft of silver coiling for 125 feet of OFC copper, damping those coils (and body with a fitted part) and adding a constrained layer wedge with maybe $5 in materials to the picture...doesn't quite add up to $1895.00.
I think you could have achieved
every bit of the satisfaction you now have by buying a wood bodied Platinum...and asking Mr. Gregory to put a new $250 line stylus on it. If you think the Isolator is beneficial (I found that critically damping that juncture between Grado cartridge body and headshell to be) - look in past articles here for
The Plast-i-Lator. Material cost for it is about 2 cents. For less than 1/3 less, I'd think you'd have all the performance of the $1895.00 MM Classic.
But, that's
just me - maybe you're wealthy

Better yet, if you have at least 56db of quiet gain available to you already, go buy the 0.5mv Platinum Reference (same price as the higher output one) and do the above and you'll have a cartridge that quite handily outperforms the Music Maker Classic. The lower internal resistance/impedance (6' of larger, LC-OFC gauge wire used) and inductance (far less turns of that wire now) will translate to more signal being passed and more extended high frequency response (less 'veiling'). You really can't get around the superiority of these raw electrical parameters....no matter how much foo-foo dust and magic is added to the cartridge formula.
I don't doubt what your hearing is fine indeed (a few of us here adore our Grado's of various price points), but I think you overpaid to the hilt on that purchase.
Sorry, to break the news to you....but guys in hifi like Len Gregory just steam me (tho he is no doubt producing a fine end result - he's just gouging folks for a tarted up Grado)