Near as I can tell from the posted pictures you have Maillard CXC pedals.
My guess is that you have the 500 model that can't be repaired.
"Baldy" has an account on his blog of working on the model 500 version, sadly he does not say how he will remove the "swaged-in bearings":
It turns out the bearings are 'swaged' in at the outer edge ...
As there are balls missing and bent components, you should completely refurbish the hub.
It looks like a freewheel type hub rather than a freehub/cassette type. First thing to do is get the freewheel off. Personally I’d replace the freewheel so I’d be starting with unworn sprockets and chain.
Disassemble the hub, completely degrease and clean and inspect the ...
That's an awesome bike - would be called a MTB back in the day, but now we'd call it a rigid MTB.
You probably have to replace the brake pads (the rubber blocks, 4 in total) because they go hard with age/ozone/UV and don't brake as well. That style of brake is called a cantilever and while less-common now, they can still work perfectly well when tweaked ...
1 Is there a consensus that renovating a classic bike from a reputable company is fair play, or would I be breaking a tacit bicycle commandment by doing this?
2 Has anyone regretted carrying out such an operation?
There is no consensus on renovating vs. conserving
There are no global tacit bicycle commandments.
There are localized tastes and ...
By way of background, this Cyclingtips article lists three general approaches to approaching classic road bikes. NB: I'm not sure if the term restoration is mainly limited to restoring components, or if it is usually understood to include repainting.
When it comes to rescuing a classic road bike, there are three schools of thought. The first is to treat is ...
That era fork will probably be spring/elastomer or spring/sealed cartridge. I believe the T2 was essentially a glorified Indy. The elastomer will have hardened and no longer be working optimally, so the shocks won't be performing like new (and when new, were not great by todays standards). The sealed cartridges were not serviceable. The play will be wear.
If by “play” you mean for/aft play between the stanchion/lower interface this will be caused by bushing wear. Those early Judy shocks have very small bushings compared to what is used today. Depending on how clean you kept the shock (the early seals were horrendous as well) the bushings would typically wear out quite fast. Each side of the lower will have ...
I don't know if you're still planning on restoring that BMX, but what I can tell you is that I have that exact same bike.
I have had mine since brand new and brought it in 1999.
I don't think it has much value so to speak, but it's been put together to compete with Mongoose.
Mine has blue chrome parts rather than the purple/pink yours has.
Does your chain ...
I don't know how to disassemble the axle to get access to the bearings. If there's no clear flats, or a 6 or 8 sided nut visible, then you might be looking at a one-time assembly.
Try turning the rosette-end of the shaft visible in the photos, using needle nosed pliers. I suspect it won't do anything.
However as a half-way option, try dropping some ...
If your Nishiki Meridian:
meets your riding needs
then it is worth getting into riding condition - especially if you do the work yourself.
Air the tires, do a safety check, and ride it around enough to get a feel for how it rides. If you like it then it's worth fixing. If you don't like it someone else will.
Type of riding
It's categorized as a ...
Normally a bike frame is designed for a specific wheel size and it's not really usual to change that size unless you go for a very specific intent.
If your frame has only v-brake or cantilever brake mounts (two types of brake that squeeze the rim in order to slow down) you must stick to the same rim diameter.
If your frame has disc brake mounts, you can fit ...
Just replacing the groupset is not enough. 9 speed cassette has different spacing from 6 speed, so the derailleur steps won't match the cogs. For 9 speed cassette, you'll need a new hub, and the new hub is wider than 6 speed so you need to spread the frame too.
There are many different 26" sizes, none of which actually measures 26". For 26 x ...
Answering your numbered questions first:
Will the rusty/blank spots be a functional problem down the line?
A: Bare steel will rust. It needs to be covered in some way to prevent corrosion.
Will power coating work well with the steel frame?
A: Powder coating is an option that will work well on a steel frame. Here is a Sheldon Brown article that talks about ...