So, for the rest of us who don't know, what was the date time frame that the Mamod forum came up with? There has to be a database somewhere with the information like:
Spot welded base was 19XX to 19XX
Crimped base was 19xx to 19xx
etc.
Jim in Minnesota
Wilesco started making steam engines in 1950 with the spot welded corners, and the D28 was
there from the start. They went to the crimped on frame corners in 1960. Going by several
other changes that took place in the mid 50s, that's where mine is, the second half of the 50s.
Some of the smaller ones were just stamped out with round corners.
So on the big ones.
Welded bases was from 1950 thru 1959.
Crimped bases are from 1960 to the present.