Ron - the manual that I have for 544s states that for both early models with B16 and later models with B18 engines, the free play should be 10-15mm or 3/8 to 19/32 inches.

My suggestion of 1/2 inch should be OK

For later cars, I have a set of green books for 120, 140, and 1800 - their free play is much less 3-4mm. Note, these assemblies have almost no linkage direct to a master cylinder.

Almost every car I have owned that had a standard shift, 61 Mini, 63 MG 1100, 49 Chevy, 53 Chevy, 66 Dodge, 63 Sprite, Gremlin - all called for 3/8 to 5/8 inch of free play. (My first car a '60 SAAB had a cable clutch that suffered a broken cable, and I never adjusted it.)

It has been my experience that many people do not understand the need for free play and adjust their clutches for a certain grab point or some other measure like the example in this thread.

It is my contention that free play should be adjusted to the proper measurement, then if the clutch is not operating properly, then the other aspects or the clutch need to be checked.