Thanks Ian, that's comforting to know. I will have it skimmed - good idea.
These tools usually work by pivoting on a bell-housing stud and the tooth on the tool drops into the teeth on the flywheel.
I prefer not to use wood anymore. Last time, when trying to remove the crankshaft pulley nut before I hired the electric impact wrench, the wood block split and I had to fish bits out of the crankcase.
I sent TotallyAlfa a copy of the special tool bulletin showing A.3.0118. My word "replica" may be over stating the case a little. Gary at TotallyAlfa said he is is going to engineer something which does the job but which is not quite so complex.
The tool in the pic is listed as a diff bush puller on a parts website so it may not be good for the gearbox mounts.
As to cost, that remains to be agreed but the figure Gary gave me as a budget was reasonable. I have sent him a new mount and I have to give him some dims of the bellhousing so he can design the tool.