The paper "North American mergers in progress" says the following; I've adjusted the formatting slightly:
In the course of the study, Telsur found evidence for a number of other mergers of back vowels before /l/ codas. Figure 9.4 shows a merger of /owl/ with /uwl/ and /ul/. Minimal pairs for these contrasts were introduced in the course of the study but not consistently over the whole Telsur sample. In order of frequency of ʻsameʼ responses, these items were:
- the merger of /ul/ and /owl/ as in bull and bowl;
- the merger of /ʌl/ and /ohl/ as in hull and hall;
- the merger of /ul/ and /ʌl/ as in the rhyming pair bull and hull;
- the merger of /ʌl/ and /owl/ as in hull and hole.
The first three of these at least deserve further study.
You apparently have mergers (1), (3), and (4).
That paper appears to be part of a project from the early 2000s. If there hasn't been more definitive research since then, you may deserve further study.