You say heading towards NW 5 which means your hairloss is progressing further, most doctors will not offer you surgery. You may end up losing a ton of native hair leaving any transplanted hair looking unatural and out of place.
As VCM stated most doctors will be cautious to say the least as they dont know how far your hairloss will progress and with you not being on any meds it makes it worse as there is nothing to stop further hairloss.
What age are you,also if you could post some pictures that would be great.
Forgive me for being so vague, I`m 33 now - my father was a norwood five at the ripe old age of 34, however he never progressed further, hopefully I`ll follow suit. I tried Propecia for three years with no results, Rogaine gave me severe scalp irritation. I`ll add some pictures shortly.
I think you will get some clinics to perform ht surgery on you if you go into it with realistic expectations. What a diffused thinner can expect eventually is to lose the native hairs, especially w/o any ht meds. What may occur, for example; a diffused thinner has native density of 30 fu's per cm2, add 25-30 fu's per cm2 via ht surgery, so the result you should get is 55-60 per cm2 but loses all native hairs so he is back to square 1 with 30 Fu per cm2. This patient will then need another ht to thicken things up.
I`ve been incessantly thinking about this,do you think your hairloss has stabalised now as a session on the conservative side may be an option for you,however this is just my non medical opinion and your best bet would be to schedule some consultations to hear what the doctors have to say.