The frame mounting pins should line up fairly well; maybe a bit of needle file work on the locator pins, maybe a bit of opening up the lug holes.
That is the least of your worries. You will also have to check the arbor length of the Uberti with the arbor recess of the ASP barrel. Once that is satisfactory, you will need to check the relationship of the wedge slot of the Uberti arbor and the wedge slot of the ASP barrel lug (front and back). Once a wedge is properly fitted, you still need to check the barrel/cylinder gap for proper clearance, and correct if needed.
You do not state what the date code of the Uberti revolver is, nor the date code of the ASP source revolver for the barrel. ASP was only in business for less than 20 years (60's-70's) which was prior to any CNC machining. The same with Uberti if the date code was prior to 2002.
I am afflicted with "parts-changer" syndrome concerning Pietta 1851 Navy .36 "type" to create several Confederate Navy "type" revolvers but have learned to stay with revolvers produced during the CNC period (2002-present) so as not to make it difficult.
I hope you are prepared to have a bit of time on your hands.
Regards,
Jim
