Andreani Cartridges in Tigga

Ok, so I spread the love around. I'm in the process of upgrading the shite suspenders in my 800 Tiger XRx. I've bought Andreani cartridges for the front end and have a Wilbers shock coming my way for the back.
Now I've got the forks out and dismantled and ready to install the Andreanis.
Trouble is they specify Ohlins 01309-01, a 5 weight oil with a viscosity figure cSt of 19 at 40 Celsius.
I cannot locate a retailer for Ohlins fork oil here is Aus. Couple in the States and, as usual, the shipping cost exceeds the product cost. I'm also impatient and want to get back up and rocking!
I can buy Belray HV1 5Weight here which has a cSt of 19.5 at 40C, but I've no idea how much the change in viscosity would matter.
Alternatively, I can buy some Motorex 4W and 5W oils and mix them - if the final viscosity ends up as the per-unit mix of oils.
That is, the Motorex 4W has cSt of 16 and the 5W has cSt of 22. Mixed together in equal quantities, will this give the predicted result of a cSt of 19?
The oil weight would also end up at 4.5 - I know you can mix to get this, but is this more important than the viscosity?
Am I over-thinking this and it would make sod-all difference if I used the Belray (cSt 19.5) or even the Motorex 5W (cSt 22) unless I was on a racetrack?
Anyone able to shed any light on this?

I think you're overthinking it. I've used off-brand equivalent fork oils (including Belray) in Ohlins and Marzocchi cartridge forks, and they worked fine. I suspect the same applies to the Andreani conversion. The difference between using a 19 vs a 19.5 is not noticeable by the normal human being (maybe by Rossi or Marquez).

Ken

Thanks Ken, it wouldn't be the first time I was guilty of overthinking things - a lifetime of design in engineering has brought that about!

Yeah, the saying in the aerospace industry used to be "it's time to shoot the engineers so we can go to production." Engineers want to keep designing until it's perfect, and the management wants to go to production way before that.

Ken

If you can tell the difference between two different-branded 5-wt. fork oils, you might want to avoid sleeping on a pile of mattresses with a pea under the bottom one.