Most has already been answered, just my 2 cents.
I both use a Tech III as well as a poor man's Tech IV (Linhof Color), as has
been said the Tech III requires is own square aluminium lens board, can be made
easily. The Tech IV and higher (as well as many other brands beside Linhof such
as Chamonix, Wista etc) use a more elaborate lens board, very expensive when
straight of Linhof, but Chinese copies (eBay is your friend) are much and much
cheaper, although people have been reporting issues with not fitting properly.
On the Copal 1: most of the slow ones I had I could get running properly again
by removing the sticky lubricant on I believe it's called the speed train by
degreasing with a nasty solvent in a fume hood. Richard mentioned lighter
fluid. And then re-lubricating very sparsely with good oil.
Compur shutters are far more complex than Copal shutters, these are fairly
simple inside. If you search carefully on the internet; there is info out there.
Best,
Cor
