New bike

starter motor - search this forum, especially posts by Peter Shand,
front brake - a 13mm master cylinder with the original brake caliper is the recommended route, again lots of advice in previous posts on this forum.

Peter Shand is your man too!
If it is savable RGM do a conversion kit to make the original M/C more efficient. Peter can do the machining and fitting for a very reasonable price. He's my go-to engineer for anything Commando related.

Regards
Eddie

Many thanks for the nice comments, I hope i can live up to them!
The original Mk3 starter has a few built in faults that will degrade its performance over time. They can be overcome and the result is a starter that is the match of any available. To do the required modifications means the use of a lathe and the skills to use said machine which for the most part puts this work into the engineers territory. 
The front brake can be made to work a lot better. It is one of these things that you can spend a lot of money on to get a better stopper. New bigger disc, Different caliper, stainless brake pipes, etc etc  The cheapest way to a better brake is the RGM kit to sleeve the M/C down to 13mm, and unless you have the required skill and equipment it does mean the use of your friendly engineer again.
Search for the articles on starters here and if you want to know more, feel free to PM me
Regards
Peter    

I did the RGM master cylinder conversion using my own drill, tap and squared up on my bench drill. A bit nerve racking but don't risk it unless you feel confident of your ability. I then found out the disc was warped so bought a floating Girling disc but had to chamfer the bottom corner edge of the caliper to clear the disc rivets., no big deal as there's plenty of spare metal. Later on I fitted a braided steel brake hose, only for fear of the original rubber one bursting, the new hose gave it a firmer feel. The front brake now has good grab at town speeds but needs a harder pull at high speeds than modern bikes but I can live with it as it matches it's mores sedate performance. 

The front wheel should run centre in the forks. Measure at the rim not the hub and line up with the headstock not the fork sliders (there's a handy hole down the middle of the steering stem). The front wheel is heavily dished to accommodate the brake and the spacers are different lengths.

Central Wheel https://central-wheel.co.uk/ are good for all things wheel related and have all the data.

And chuck an 18" rim in the back so you can find tyres.

I prefer Devon Rims to Central Wheels!  I have an original full width wheel that has butted spokes, My rear wheel was rebuilt with a set of Central's spokes which are un butted 9 gauge by a competent wheel builder, sadly I've had two spokes break in the last couple of weeks at the hub end si I am going to have to do it again with butted spokes. My thought is that plain 9 gauge stainless spokes aren't up to the job (this is on my es2) and that butted spokes are preferred.  My opinion anyway!

Dan