Z1OwnersClub GB

Afternoon, Guys,
Well its been a while, bike restoration put on hold for a while as ive moved house, there was lots to do. So bike resigned to garage.
However now trying to get back on with it as would really like it on the road for 1st April.
So hoping someone more knowledgeable can help.
Firstly 6 months in garage took its toll on old Takasago front rim, it was always a bit rusty and spokes had been sprayed silver, nipples rusty too. The rear rim had already been replaced previously with a none marked new rim, but spokes sprayed again so these were replaced with new ones from Zpower. I used Phillipes wheel guide and fitted them myself, went well and hardly any trueing needed.
So decided to bite the bullet and replace front rim and spokes as a set.tried to get a genuine Takasago but their really pricy and not always any better then mine now, i also looked at re chroming but again mega bucks and massive lead times, so decided to replace with a brand new Chromed British rim or correct size and width, bought brand new spokes/nipples from Zpower and started to lace wheel again as per Phillipes guide. Got wheel laced ok, but was unable to true it up, tried for several days and gave up, found an old school guy who does nothing but wheels, all local motorcycle shops use him so must be good.
Took wheel to him and he asked if id take old rim too.
He checked new rim against old one and agreed they were a match, but then went on to say the spikes looked wrong length? I told him id bought them from Zpower and are correct ones for my bike, he then went on to explain that each rim can have diff spike angles, diff depth of bead etc, etc, he said its not just about hub, the rim and the spokes but they all have to match, had i checked the offset on original front rim? Who knew?
He said he would try to build it up and true it but apoarently spokes cannot have any thread showing and thinks they look to small, or nipples too short.
So question is this correct, I assumed as long as spokes tight and rim true that was enough.
Can anyone shed any light on this, or tell me the front wheel offset ie distance between hub straight line upwards to wheel rim.
Thanks

Ok well got wheel back from.wheel builders perfectly true, i checked in my home made jig before re fitting tyre, he said the spokes were fine and torqued them to correct tension. There is a thread showing on a few of them which he would have preferred not to have but stated there was enough thread on nipples not to cause any issues.
The reason for the difference is the Takasago rim has a slightly deeper nipple rebate on the rim, only a mm or so but it obv makes a difference. Apparently my re lacing of the wheel was correct and didnt need any alteration, after 3 days of tinkering trying to get it straight, I'd had enough as I wasn't getting anywhere. Plus wasnt 100% sure spokes were correct or even rim or my lacing ( reading Phollipes post def paid off thanks). So good news all round.
Best news only charged me £10 which was a bit of a bargain i think.