Leak down test

Yes, hope Dee is ok too.

The oil  pressure is running on the bypass. Is the pressure sender before or after the filter? 
Wait till it gets up to full temp and the idle pressure should drop.

With photo #2, I thought you'd cut a hole in the roof for the exhuast.   Took a bit to work out that it wasn't a hole. 

Sender is plumbed into the block before the filter. IT has never dropped from this reading unless i shut him down.

As for Dee, we will know more hopefully tomorrow afternoon. While waiting for that I have my annual cut n freeze session at the skin cance clinic for the annual cut n paste.

As the oil is going via the bypass little if any is getting filtered so you need to reverse whatever you did prior to the rebuild.

Cobbadog, I wish you and Cobbarette all the best. Please pass on my love to Dee. She might remember when you came down to see me and our collection. It's about time you both called in again. The place has improved a bit.

Morris.

Sender is plumbed into the block before the filter. IT has never dropped from this reading unless i shut him down.

This is then just measuring the oil pressure release valve setting.   It's not measuring the oil pressure in the oil gallery which is where the oil pressure drops off as the oil drains past the bearings.

The sender should to be plumbed into the gallery after the oil filter. 

It's possible that the pump is high volume and is capable of maintaining 40psi  in the galleries at idle and high revs.  But generally, one expects to see a fluctuating gauge as revs vary.

Where it's connected us the one n only place for oil pressure gauge to be fitted, there are no other options so can't see how it's wrong

I'm with jon_d.

I'd like to find a way to have the sender after the filter.

Too suspicious have 40psi at idle on any Pommy engine.

to change it to anywhere else you would have to guess where the galleries are. Its dsetup as per the manual from DB. As I said I lifted te pressure when there was a bearing issue with them badly worn. 

Seems to be common sense to have pressure after the oil filter (if it is full flow. If just bypass makes no difference

I suppose you have this manual with no specific answer other than relief valve set to 40psi.

  bundybearsshed.com.au/wp-content/uploads...Book-DBT301-1953.pdf

It's not a problem if you KNOW the filter isn't blocked or even partially blocked.