Howdy Rouge:
Q1: is the original lifters hydraulic or mechanical in the head of a 200c.i. ?
A1:To clarify, the lifters are in the block. THe original lifters in engines from 1960 to 1964 were solid type lifters. The rockerarms were adjustible. Hydraulic lifter blocks were introduced in the 1965 model year.
Q2: is it possible to swap the one with other one ?
A2: It is possible but will not function as designed. In other words, the hydraulic lifters will physically fit in an early solid lifter block, but will not work as hydraulic lifters, because the early blocks were not plumbed for hydraulic lifters.
It is possible to use a solid lifter in a hydraulic lifter engine, but you must use the adjustible rockers and pushrods to be able to adjust the valve lash.
Q3: is it possible to put an hydraulic lifter with an mechanical push rod and rocker ?
A3: Yes, the early adjustible rocker arms and pushrods can be used on a later model hydraulic lifter engine. The adjustibility is an advantage in getting the most out of hydraulic lifters.
Can't help with your last Q. Sorry.
Adios, David