What track bike (for the track)?

difficult to advise seeing as you just discounted some of the most serious contenders...

most alloy frames of a certain price point will be nicer on the boards than some vintage thing. Unless you are an adamant luddite, or on a budget, there's no advantage in old steel bikes on tracks like this.

The rational side of me says buy one of those, it just feels more like buying a washing machine or a 'fridge. The Tiffosi is more than I'd ideally spend but looks stunning VFM with £300 off