Wotcha Gav,
I have to say that techniques are different from one piece to another.
In a previous life I used to restore 'antique' bears and stuffed toys. So mohair, felt and other natural fabrics etc.
I'll share the techniques as they are transferable.
Firstly I'd say that when attempting to clean any old fabric there are a few things to keep in mind at all times.
Colours are unlikely to be 'colour fast'. Keep the item as dry as possible. Often as with cleaning a blade, less is more and you are better to aim for 'nearly clean' than 'really clean'.
I would recommend the following items of 'equipment'.
Clean absorbant soft white cloths (pre-washed and well rinsed before drying)
Sponges.
various brushes (toothbrushes, shoe brushes, record brushes)
A good hair dryer with various settings hot and cold.
Paper towels (white only, NOT coloured or patterened)
Various detergents.
I used to have a selection, but my favourites were stain removers for delicate handwashing (If memory serves one made by Ecover was good, but there are many options). Also I used to like aerosol foaming upholstry cleaners for cleaning car interiors. I also had carpet cleaner and washing detergents (usually the ones for delicates and silks are best).
So, the technique depended on the fabric and lever of soiling.
Basically the quicker and 'dryer' the cleaning the more likely that it won't cause any harm.
With any item you are cleaning tackle each panel of material as if it was a different material even if it appears to be the same type. Test first to see if the colours are running/coming out. Slightly warm water with some detergent (go with mild and weak first) use a clean white cloth to dampen the area to be cleaned, with a pressing motion not rubbing (if you can help it).
Test straight away by pressing a clean white paper towel onto the wet area to check whats coming back off with the water. If cleaning something with plush like velvet then gentle brushing might help. Always brush 'with the grain' never scrub.
Use the paper towels to get most of the moisture off, then dampen again with clean water and towel dry before drying properly with the hairdryer.
Always clean one area and dry it with the hairdryer before starting the next area. Don't leave one bit damp and start another as the colour might start to run or the old fabric might deteriorate in other ways if left damp for longer than needed.
Slowly does it. If anything looks wrong, plush starts dropping out, colours start running, you can stop before any harm is done.
Clean paper towels are a must as they will absorb any water and dye coming off and warn you of any problems in time to stop before it's too late.
Don't be tempted to use a patterened paper kitchen towel as you'll tranfer the patern onto the fabric.
You can try various techniques on a single item. You might use some spray upholstry cleaner or mild detergent on the main areas but some stronger solution or even carpet cleaner on one soiled area (after testing of course
)
Best
Gene