I made the link pins out of 14mm "silversteel"; to ensure a good fit, a rather complicated set-up on the lathe was used to drill out the remains of the old pins and ream to 14mm. The double length links pins were hard-soldered pair-wise, and then cut off in the middle, so the pins were absolutely parallel (am I a bit clear 
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Worked well, and cheaper than NOS links (IF you can find them
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The useless bushes were replaced by bushes made from standard bearing bronze and reamed in place.
email (option): viaconsu # planet dot nl
I wouldn't consider silver steel suitable for fork spindles. It is a flame hardening tool steel and if quenched after brazing/welding it will be very hard but also very brittle. Tempering in the home workshop is also an imprecise procedure unlikely to produce a consistent or verifiable result.. If left to cool naturally wear resistance is poor and strength moderate.
A high tensile steel such as EN16 (BS970)(US 4037) is far more suitable as it has both the required strength and wear characteristics in it's 'natural' state.
However, this is a medium carbon high tensile steel. As such, and typical of these types, its weldability is inversly proportional to the carbon content...ie the higher the carbon content the more difficult to weld without losing strength/hardness..
As a result if I was doing the job myself I would either thread the links and pins and screw them in or drill and ream the links and press in a 'shouldered' pin...probably the latter. A .0005"-.00075" interference fit on a 1/2" spindle would be ample..Ian
email (option): ian@wright52.plus.com
Oilite is manufactured using a 'powder metallurgy' process which results in a porous granular finish. Oil is impregnated into the bush at the manufacturing stage under a vacuum.
There are various types of oilite bushings with varying properties and in principle they can be used for girder forks if the correct type are selected.
However, one key thing with oilite bushes is that they must be machined with very sharp tools. This is to avoid 'smearing' the material which will block the porous structure, seriously reducing the lubrication and thus its operating life.
Reaming, in particular, is not recommended as a cutting method.
It is highly likely that the bushes were reamed when fitted, which may explain their short lifespan...
Bearing all this in mind and the fact that ideally the fork bushes should be line reamed to a finished size, a standard bushing bronze such as PB1 would be more suitable as it is less prone to suffering problems during fitting...Ian
email (option): ian@wright52.plus.com
The original links weren't hardened. However, they would have been made from at least EN8 I would imagine and more likely EN16. EN 24 would be 'over the top' for this application.
EN16 would give them good load bearing capabilities combined with reasonable wear resistance in its untreated state.
Silver steel is a high carbon tool steel, in fact it has the highest carbon content of the tool steels. This means it can be heat treated to a high degree of hardness for the applications for which it is intended such as the manufacture of razor blades, drills etc. etc. which have to retain a sharp cutting edge.
For reference EN numbers were introduced in the war (Emergency Numbers) and although still often quoted they have been superceded by BS (British Standard) numbers. EN16 is now BS970.
Regarding the bronze bushes PB1 bronze is suitable. This is available in bar and tube form.
It is suited to medium to high loads with good resistance to impact loadings. Corrosion resisatnce and machinability are both good.
Lubrication is important with this material though so the oil scrolls present in the original link pins should not be omitted and the bushes should be greased regularly with a light grease...Ian
email (option): ian@wright52.plus.com
Ian, I spark-tested the material I used some 10 years ago, and it is NOT silver steel, but so-called axle steel, a low carbon construction-grade steel. Can't be hardened, only pack-hardened
email (option): viaconsu # planet dot nl