Hey George,
Here's the basic do progression as I recall:
ERIE with flat top but some had a slightly domed cover. Maybe these were the later ERIE pots. 8 was the smallest. Some early probably do not have pattern number and cover may have a knob instead of the usual handle. I've only seen one and do not remember it clearly.
Addition: Late in ERIE production (c.1905-10?) a No.6 and No.7 ERIE dutch oven were added to the line.
Slant/ERIE with a low domed cover and "applied" handle which is not really applied after the casting. Only pattern number on inside of cover (and size number??). I can't think of any of these with the TM inside the cover. There are probably differences in some of the larger sizes. No.6 is smallest. All from here should have pattern number and Erie on the bottom up throught 1957.
Slant EPU (Erie, PA, USA) Tight Top Baster. First covers with Patent Appl'd For. The patent date of Feb. inside the slightly later covers refer to the basting rings. The March 1920 date on the pot's bottom refers to the locking bail attachment ears.
Slant(?) EPU Tight Top Dutch Oven with low domed cover and round handle like earlier do's
Note: I have had, and have photos of, a low dome Tight Top Baster do cover with the slant TM. I believe it was the same pot which had a Tight Top Baster bottom with a BLOCK tm. The two photos are together in my old Cast Iron Cookware News on p. 83 if anyone has a copy and wants to see them. This seems strange that the later block TM is on an earlier Baster pot while the later Dutch Oven cover has the earlier slant TM. I am assuming the Baster was earlier than the Dutch Oven markings and also think there may have been some overlap in production. Or, did Griswold sell Basters in some parts of the country and Dutch Ovens in others for a time? Another strange sequence of unidentified events from Griswold. Being as how the covers were not cast at the same time as the bottoms, it is conceivable that Griswold shipped whatever they had on hand even if the TM's or other wording on the pots were not matched.
Block EPU Tight Top Dutch Oven with high domed cover with angular handle like later do's.
Earlier ones were gated at the bottom of the straight sides as the sides rolled into the bottom. Later ones were not gated there but were on the top, outside rim. I think all sizes at least 6-10 can be found in the later style which gives a nicer cast pot.
1930's style with the rounded bail attaching ears. I think the button logo covers were the first ones and, later, the TM on the covers was removed but I am not certain about this. Could be that the logo covers came later although the very last ones were smooth tops. Medium large TM's for a long time with the last of production changing to small TM at least on the No.8 pot. I don't know if other sizes of do's were made in the later (c1950's) years.
I don't know where the pot size was first put on the top of the pots' ears but it was there on at least the later Block TM pots and possibly earlier. I would think you might have an early marriage with your pat. appl'd for cover with the pot with number on top of handle but maybe not. May have missed some details here as it's been a long time since I have had many of these do's.
Steve