Abide by the physicians' code of conduct - do no harm. Most importantly this means do not irreversibly modify originality on any component! This includes not only design but finish as well.

Put carpet on your workshop floor - it saves lenses and other delicate parts when dropped. However, It does make finding small screws more difficult. I suggest you use your bare hand in a large-area swipe across the carpet while at the same time scanning a flashlight beam parallel to the floor with the room lights off.

Use dust mask for particles; chemical masks for solvents. This is important if you want to be around to enjoy your collection.

Wear tight fitting vinyl gloves, or suffer painful cracked deep fissures on your fingers from sanding, steel-wooling, buffing, waxing, polishing, staining, and lacquering/varnishing.

Store wooden tube telescopes in a 40-50% relative humidity area. This will help reduce shrinkage and cracking at the dry end of the relative humidity range and mildew and corrosion on the other end of the relative humidity scale.

Enjoy your work.

Never remove or insert a slotted-head screw with one-hand - if you slip, you are likely to cause deep scratches.

Have access to special machinists that know what they can and can't do, but are willing to try new things.

Get to know your local musical instrument repair specialists - they know brass!

Become good friends with the best wood craftsman in your area.

Marry an understanding spouse with great forbearance.

Use large, shallow baking pans as catch basins for disassembling and assembling telescopes. If you drop a small screw or part, it is in the pan! Also, the project can be moved off the workbench at any time. (See photo below.)  Case in point: A couple of years ago I dropped a small (3-mm diam.) keepered (square hole) tapered compression brass washer on the floor six feet from where I found it 2 months later inside a small empty Kleenex box sitting at the other end and on top of my workbench. I found it on the very same day I picked up my newly machined, expensive to make, shiny new small (3-mm diam.) keepered (square hole) tapered compression brass washer! If I did not believe in the laws of physics, I would have to say voodoo or some form of witchcraft was at play here.

Stock many small zip lock plastic bags for keeping and cataloging small parts - they, too, are indispensable. (See photo below.)

Start restoration early - that way you will not accumulate more "stuff" than you can restore.

Same grit sandpapers by different manufacturers do not leave the same surface finish on brass. They must have different shape and composition abrasives, even though their on-average or median micro-particle size may be the same.

Create a pleasant work environment in your workshop - you will spend more time there than you think.

Put a lock on your workshop door. You may wish to protect your work in progress.

Put in a large supply of paper towels.

Document all your work in writing with supplemental sketches and photos.

After restoration hire the best photographer you can find and afford; unfortunately if they are really good, your restoration work will not appear as impressive and you will really have to worry about dust and lint on everything that is photographed.

If possible set up or have access to optical test equipment to characterize your objective lenses and primary mirrors.

Provenance is at the heart of a quality antique collection. The signatures found upon the telescopes aided the provenance for my collection considerably. Even so, there is much unknown about many of the telescopes in my collection. This is unfortunate because each telescope carries its own exciting and unique story.