CheeseBurger,
The only left hand action made by HVA is the 1900. There is no 1640 made for lefties.
Regarding your 1640, I am not sure what it is. The alloy bottom metal was not into production before S/N 220 000... so, tho me, your rifle had a stock swap or the alloy bottom metal was fitted to an early stock.
The 1900 were made in a lot of calibers, including the 6.5X55, but there are just a few in that caliber in Canada. But there are a lot of them in Sweden.
Camp Cook,
I am not sure about this (new?) Husqvarna Huber Concept trigger, as they show a M/38 rifle and by reading it, it seems they also make them for Service Match which calls military rifle to me.
The thing I can say for sure, is that a M/98 sporting trigger fits both the 1640 and the M/94/96/38.
The main difference is in the sear design, but a M/98 sear fits the 1640.
The main difference for the M/94/96/38 sear is that it have a projection at the front which engages a notch under the bolt. I'll try posting a picture of them all later today or tomorrow.
Anyhow, to answer your question, it should fit, but a M/98 one fits too.