Linothorax design/construction

[Paullus Scipio]

One thing that came in mind...Xenophon says "spolades kai thorakes" for the cavalry armour of his troops?Then,what troops is he talking about?There was no cavalry in their original army.

That is quite right, Giannis ! But you should read Xenophon more fully.
After Cunaxa, the Ten Thousand find themselves harassed by Tissaphernes with about 400 missile troops (slingers and archers who outrange the greek 'akontistai'=javelin throwers) and 200 cavalry, who ride up and hurl javelins at them, then ride off with impunity.
Xenophon proposes that they raise slingers of their own from the Rhodians in their ranks, and since these use lead bullets, they will outrange the Persians.He also propose they raise some cavalry.
That night, 200 slingers are raised, and the next day some 50 horses and riders were passed fit for service. Because they are unshielded, they need body-armour protection, so they are given breastplates(Thorakes) and tube-andyoke-corselets (spolades) - which must be donated by Hoplites - and Lycius the Athenian is given command.

And surely hoplite armour cannot be intepreted as bronze muscled cuirasses for the majority!

Indeed not ! Xenophon's preference elsewhere is for Bronze cuirasses for cavalry, but the inference here is that fewer than 50 were donated, so the rest had to make do with 'Spolades'.

.Also,I don't know what ammount of these hoplites had any body armour at all.

Obviously many did. It is something of a myth that unarmoured Hoplites appear later. It is clear that Hoplites without body armour had always existed. It is Art that changes, rather than equipment, so the idea that Hoplite equipment got lighter in the sense that body armour was abandoned, is really not provable and rather unsustainable.

This last one is pure guess,but wouldn't you agree?

Not really.Xenophon recommends the heaviest protection for cavalry, and the 'Thorakes/bronze breastplate' is his first choice ( see "On Horsemanship" )

new land for investigation

.......yes, that is where we want to go ! D Surely we can all agree on this ??