Fisher Tube Receivers rated vs. modern seperates

How do Fisher 800C and 500C tube receivers match up versus modern seperates? Ive had the preamp and amp sections seperated on my units (a $50 job from a competent tech). Ive tried subbing several other phono stages from recievers and preamps, as well as subbing just the preamp with some under $1000 preamps. I've also subbed some high power Denon monoblocks ($500) for the amp section.
Admittedly, none of my substitutions have been with Sterophile rated phono sections, preamps, tuners, amps, or headphone sections. However, I have made several switches with Stereophile Guide to Home Theater AA and A equipment. So far, nothing has been better than a well performing Fisher Tube amp. I know my preferance for 'that tube sound' has biased my opinions.
Well, now I have more money. Most people polled have said that to replace the Fisher with equivelent quality new stuff would cost $1500 to $4000. Most people say that the preamp section is the weakest. I'm thinking of trying a Rogue preamp in my circuit.
Anyway, what do you think? For me, the Fisher receivers have been an ultra cheap entry into the world of high end. Ive tweaked with isolation and vibration control, racks, cables, speaker placement, cleaning connections, power supplies, power filters and power cords, and interconnects and front end gear improvements. I've heard noticable improvement with each tweak, and now it's time to find something superior to my Beloved Fishers.
What would you do?
My vote for replacement value of sections (used equipment on AudiogoN):
Phono: $225
Preamp: $500
Amp: $800
Tuner: $600
Headphone amp: $200

Thanks for your time. I look forward to hearing what anyone with experiance upgrading from Fisher tube receivers has to say.
I can't advise you on how to upgrade from your Fisher tube receiver. However, as someone whose first major audio purchase in the early 1960's was the Fisher 500C receiver, I implore you NOT to sell your Fisher tube gear, unless you get an insanely great price from a Japanese collector. All of the Fisher tube gear is classic, and you are a fortunate guy. Sure wish I still have my old Fisher tube equipment.

If you and other Fisher fans are interested in looking at some of the Fisher gear from the 1950's and 1960's, check out the following Web site:
I think you would get more bang for your buck with a used tube integrated amp. Rouge Tempest? I agree with Sd, hang on to the Fisher for life.
You may not be able to replace that sound you love with a new component without spending thousands. I cringe when I think of all the modern amps I have bought trying to better my Fisher 15 watt mono's... Cary SLA 80, VTL Tiny Triodes, Adcom 565 Mono's... they're all gone now. The only thing that comes close is some of the single ended stuff, but then you have the problem of even lower power and speaker limitations not to mention price. I will admit that my Cary SLP90 is better in most ways than my Fisher preamp, but, with the power amps it is no contest. Also, these old preamps are just full of sound degrading switches and filters, etc. and could really benefit from hotrodding.
I wanted to point out to anyone following this thread that reasonable, working Fisher 800C or 500C Receivers can be had (usually on eBay) for $200-$300. A good going over by a competent tech will cost $50-$150, and new power tubes are now available for $90/quad.
I second the hotrod motion. Bypass all those switches and tone controls! AND definitely hold on to it. You can't get alot of $ for it any way so...

I have a 500C that I hotrodded. My main system, however, is a tweeked Cary SEI 300BLX20 and it's definitely a step up but also in price, not to mention cost of pre and tuner. I've got the Magnum Dynalab FT101A and it's clean but it ain't tubes.

I've also rebuilt a bunch of Dyna SCA 35s. They're alot cleaner and leaner and MUCH easier to work on; no tuner though.