Manual out of date?

This is possibly a really stupid question but....
Whilst having problems with a reconditioned engine, the last mail that they sent to me (before they inexplicably stopped replying, probably computer problems. I expect) implied that I shouldn't go by the manual as there more modern ideas now.
Specifically...
1. There was no oil pump gasket. They said that they are not used anymore but I think they still come in the gasket set. Does nobody put these in now?

2. The piston/bore clearance was 4-5 thou instead of the 1-2 I expected from reading the manual. They stated that different piston makers had different clearance and I would be wise to use current specs instead of relying on those of the past (I.e. The manual).
Unfortunately they didn't say if 4-5 was correct or what make the pistons are. There are no makers marks on the Pistons do could 4-5 thou be the right clearance?

3. There was an oil from flywheel area. When I took the housing off, the sealant bead looked like this....


That's not what the manual says and previously I put the sealant around the crankshaft bit or use a 200tdi gasket. Their response was to imply that there could have been no leak as the engine had not run and not say anything about the sealant so I guess that means they think it's correct. Have I missed the latest manual?

Am I totally out of date or are they bull****ting?

pump should have a gasket ,though you could use sealant i use them still as they do come in the set and as it has a narrow side you know gasket will seal properly,what make of piston is it they have used ones from the 1940s/50s? gone are the days that much clearance was necessary,
200tdi gasket cut down is very good or sealing around the machined face behind crank boss including main cap joins, you can seal were they have but it wont stop rear main cap leaking oil