I have always vaped tobacco flavours not because they taste like a cigarette but because they are more like a cigarette than custard is.
I suspect that concentrate makers will name their concentrates Lambert & Butler, Golden Virginia or whatever because they know there will be a market of people trying to recreate these flavours.
All my mixes still contain a Golden Virginia concentrate because that was what i smoked and it turned ou to be a non ofensive flavour but with little relationship to an actual fag. To this gv concentrate I will add some ry4 and some cuban cigar then perhaps another baccy flavour or two and perhaps a couple of non baccy flavours.
Do my mixes taste like a fag ? No, but they suit my taste better than any single baccy flavour.
My advice is, buy your L&B flavour and some other baccy flavours, mix them as single flavours and see what one you like the best, that will be the dominant flavour in your mix, Any flavours you really dislike are useless, the other flavours will probably work as background flavours. With each batch you can slowly improve your baccy flavour.
AS a starting point your L&B mix will probably be better with some sort of ry4 or its many variations.
You can look for a recipe but you will get something that suits your taste better by gradually developing it yourself.