Over the years Bayko through Plimpton and Meccano made 128 different parts. Most in the earlier days where Bakelite, these towards the end of Bayko production became plastic. A number however where Metal.
No Bayko model could be built without the base. Charles Plimpton started with a large brown base however in 1939 he changed it for a smaller base that was still going when Meccano stopped production of Bayko. To make larger models 2 or more Bases needed to be joined together this could be done by means of metal base links and screws, these gave a very secure connection, strong enough for the model to be easily picked up. The smallest sets only contained 1 base, the largest varied, prewar the set 6 contained only 4, in 1951 Set 4 was launched with 8 whilst Meccano in their largest set reduced the number to 6. However in practice with a bit of imagination the number of bases that could be used is only governed by the number a builder has and/or the available space.
Into the base went metal rods (originally called wires). These varied in size from half a brick to 8 bricks in the sets, but up to 12 bricks could be bought as spares with larger ones made to order. Once the rods where in the base the building parts could be slotted in, including bricks, doors windows, steps etc to make the building.
The final piece in most instances was the roof, this may be a simple flat roof, two flat roofs with 2 roof ends to form a slope, an slope called a gable. The most used roof in Plimpton days was the hipped roof that came in small medium and large sizes. The roof's could be finished off with a chimney.