Help! My A's engine is "stuck"

[LizardsA]

Hi all,
I have just received my A's engine back from having the flywheel balanced and centred, as well as a new clutch and clutch pressure plate installed.
I put the engine into the car, and when I came to trying to set the timing using the crank, the engine will not budge one iota. The gears are in neutral.
What can the problem be?
Kind regards
Mike
Johannesburg, South Africa
1930 Sport Coupe