I have a Borg Warner type 35 Gear box out of a 1982 Daimler Sovereign.
I had it completely reconditioned in 1995 but in never went back in the car.
I have the receipt. In storage it copped a bit of water down the bottom and a tiny spring and lever need replacing.
The spring required is the one numbered 69 on the attched diagram.
SCParts.Co.UK part numbers 355494 and 355542.
Phone 0447 713345 ( leave message please and I will call straight back)
Victoria Point, Queensland.
Note, there is a small cost, you will have to chat to me about Jaguars for 10 minutes?