I think the a65 original material was VP23 a type of leaded bronze i believe.
The VP23 was a steel outer with an inner steel backed bush with VP10 leaded bronze material, a sales dept way of differentiation. This had a lower lead level than the big end VP2 and so did not need the overlay plate to protect the lead from acid leeching. VP10 bushes are very popular as a small end bush material.
To replicate the VP10 you need the following bronze.
Pb 10% Sn 10% Cu 80%
VP2 has 23% Pb, 1.5% Sn and 75.5% Cu
As a fully Bronze bush you lose the strength of the steel backing, so it will not have the same properties especially likely to have a lower fatigue strength. In a main bearing this may not matter but there is also greater risk of distortion from loading.